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273 Cards in this Set
- Front
- Back
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Name the three ways that heat can be transferred? |
Heat can be transferred from place to place by conduction, convection and radiation. |
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What is Infrared radiation? |
All objects emit (give out) and absorb (take in) thermal radiation, which is also called infrared radiation. |
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The ..... the object, the more infrared radiation is gives out. |
Hotter |
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Why can infrared radiation pass through a vacuum? |
Infrared radiation is a type of electromagnetic radiation, which involves waves rather than particles. |
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Name one presence of infrared radiation in everyday life? |
The sun |
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What materials are good emitters of infrared radiation? |
Black, Matt surfaces |
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What materials are good absorbents of infrared radiation? |
Black, Matt Surfaces |
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What materials are poor emitters of infrared radiation? |
Light, shiny surfaces |
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What materials are poor absorbents of infrared radiation? |
Light, shiny surfaces
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What does The kinetic particle theory explain? |
It explains the properties of the different states of matter. |
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Describe the arrangement and movement of particles in solids?
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Movement: Vibrate about a fixed position |
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Describe the arrangement and movement of particles in liquids?
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Arrangement: Close together in a random pattern Movement: Move around each other |
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Describe the arrangement and movement of particles in gasses?
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Arrangement: Far apart in a random pattern Movement: Move quickly in any direction |
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Give two properties of solids and why they are like this
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1. They have a fixed shape and cannot flow because the particles cannot move from place to place as they are in a fixed position 2. The cannot be compressed or squashed, the particles are packed tightly together and have no place to move to |
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Give two properties of liquids and why they are like this?
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1. They flow and take the shape of a container because the particles can move around each other 2. The cannot be compressed or squashed as the particles are packed tightly together and have no place to move to |
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Give two properties of gasses and why they are like this?
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1. They flow and completely take the shape of a container because the particles can move quickly in all directions 2. They can be compressed or squashed because the particles are far apart and have space to move into |
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What are poor conductors of heat called?
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Insulators |
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What are good and bad conductors of heat?
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Good: Metals Bad: Non-metals and gasses |
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Describe heat conduction in metals?
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1. Electrons in metals leave their atoms and the metal atoms left behind become electrically charged ions 2. The ions are packed closely together and vibrate , the hotter the metal the more kinetic energy the ions have 3. The kinetic energy is transferred from the hot parts of the metal to the cool parts by the free electrons, these move through the structure of the metal colliding with ions as they go |
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In what substances can heat convection take place?
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Water and gasses as the particles in these fluids can move from place to place. |
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Describe the process of convection in a liquid?
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1. Liquid particles are heated and have more kinetic energy 2. Liquid particles move apart and expand 3. Particles take up more volume as the gap between them expands 4. The hot liquid is therefore less dense than the cool liquid 5. The liquid rises and the cool liquid sinks |
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What happens in evaporation?
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Evaporation involves a liquid changing to a gas
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Describe particles in evaporation?
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1. Particles in a liquid have different energy levels 2. Some have enough energy to escape from the liquid and become a gas 3. The remaining particles have a lower average kinetic energy than before 4. So the liquid cools down |
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What happens in condensation?
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Condensation involves a gas changing to a liquid.
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Describe particles in condensation?
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1. The particles in a gas have different energies. 2. Some may not have enough energy to remain as separate gas particles. 3. The particles come close together and bonds form between them. 4. Energy is released when this happens. |
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What three things increase the rate of evaporation?
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Increasing: 1. The temperature of the liquid 2. The surface area of the liquid 3. The amount of air moving over the surface of the liquid |
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What effects the rate an object transfers energy by heating?
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1. Surface area and volume of the object2. Material used to make the object3. Nature of the surface that the object is touching.4. The temperature difference between the two objects |
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Describe elephants adaptations to transferring heat?
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Elephants have large ears with a large surface area compared to their volume. These allow heat to be transferred from the elephant to its surroundings.
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Describe the differences in ear sizes between a fox living in the desert and the arctic?
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The arctic fox has much smaller ears than the fennec fox, which lives in the desert. The arctic fox must conserve its heat energy in the cold climate, while the fennec fox must avoid overheating in the hot climate.
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How are household radiators adapted to transfer heat quickly?
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household radiators are thin and flat, and may have fins so that heat energy is transferred to the room quickly.
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What do U-Values measure, and what is a good U-value?
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U-values measure how effective a material is an insulator. The lower the U-value is, the better the material is as a heat insulator.
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What are the units for U-values
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W/m²
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What is the payback time equation?
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payback time (years) = cost of installation (£) ÷ savings per year in fuel costs (£)
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What is payback time?
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Energy-saving solutions cost money to buy and install. The payback time of an energy-saving solution is a measure of how cost-effective it is
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Describe how solar panels work?
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1. Cold water is pumped up and transferred to a storage tank. 2. A pump pushes cold water from the storage tank through pipes in the solar panel. 3. The water is heated by heat energy from the sun and returns to the tank. |
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What are the advantages of solar panels?
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1. Solar energy is a renewable energy source 2. Nor harmful polluting gasses are produced |
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What are the disadvantages of solar panels?
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1. May only produce very hot water in hot climates so a boiler might be needed in cooler climates 2. Solar panels do not work at night |
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What is the difference between heat and temperature?
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Temperature is a measure of how hot something is whereas heat is a measure of the thermal energy contained in an object.
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What is heat measured in?
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Joules J |
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When heat energy is transferred to an object, its temperature increase depends upon the....?
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1. The mass of the object2. The substance the object is made from3. The amount energy transferred to the object.
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What is specific heat capacity?
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The specific heat capacity of a substance is the amount of energy needed to change the temperature of 1 kg of the substance by 1°C.
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Why is water having a high heat capacity useful?
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Water has a particularly high specific heat capacity. This makes water useful for storing heat energy, and for transporting it around the home using central heating pipes.
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What is 'E' energy transferred measured in?
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Joules
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What is the mass of a substance measured in?
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Kilograms |
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What is specific heat capacity measure in?
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Joules per Kilogram °C
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What is the sentence used to memorise energy names?
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Most Kids Hate Learning GCSE Energy Names.
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Use: 'Most Kids Hate Learning GCSE Energy Names' to name the different energy names
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magnetickinetic (movement energy)heat (thermal energy)lightgravitational potentialchemicalsoundelectricalelastic potentialnuclear.
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Describe magnetic energy?
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The energy in magnets and electromagnets
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Describe kinetic energy?
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The energy in moving objects – also called movement energy
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Describe heat energy?
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Thermal energy
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What is light energy also called?
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It is also called radiant energy |
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What is gravitational potential energy?
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It is the stored energy in raised objects |
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What is chemical energy?
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The stored energy in fuel, foods and batteries
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What is sound energy?
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The energy released by vibrating objects
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What is electrical energy?
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The energy in moving charges or static electric charges
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What is elastic potential energy?
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The stored energy in stretched or squashed objects
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What is nuclear energy?
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Energy stored in the nuclei of atoms
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What is the rule of energy (i.e in Sankey diagrams)?
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Energy can be transferred usefully, stored or dissipated. It cannot be created or destroyed.
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What is the efficiency of an object?
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The efficiency of a device is the proportion of the energy supplied that is transferred in useful ways. |
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What units does efficiency have?
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a decimal or percentage |
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What two things effect the rate that energy is transferred to an electrical appliance?
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1. Its power 2. The length of time it is switched on. |
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What is energy transferred measured in? 2
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kWh (kilo watt hours) OR Joules |
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What is power measured in? 2
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kW's OR Watts
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What is time measured in? 2
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hours OR seconds |
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What do electricity meters measure, and how does this effect the cost?
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Electricity meters measure the number of units of electricity used in a home or other building. The more units used, the greater the cost. |
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How do you work out the cost of electricity? And what equation on the formula sheet can you use for this? |
total cost = number of units × cost per unit E=Pxt |
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What are the fossil fuels? |
The fossil fuels are coal, oil and natural gas. |
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Describe fossil fuels and where they come from? |
They were formed from the remains of living organisms millions of years ago and they release heat energy when they are burned. They are non-renewable. |
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Give the disadvantages of fossil fuels? |
1. Fossil fuels are non-renewable energy resources 2. Coal and oil release sulfur dioxide when they burn 3. Fossil fuels release carbon dioxide when they burn |
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What does the release of sulfur dioxide cause? |
It causes: 1. Breathing problems for living creatures 2. It contributes to acid rain. |
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What does the release of carbon dioxide cause? |
It's release adds to the greenhouse effect and increases global warming. |
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What is carbon capture? |
It is a rapidly evolving technology that involves separating carbon dioxide from waste gases. The carbon dioxide is then stored underground, for example in old oil fields or gas fields such as those found under the North Sea. |
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Why is carbon capture needed? |
To prevent carbon being released into the atmosphere |
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What are the two main nucelar fuels? |
The main nuclear fuels are uranium and plutonium. |
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Describe how bruning fossil fuels produces energy? |
1. Coal stores chemical energy 2. Energy transferred as heat when burnt 3. Water heated up to make steam 4. Steam rises and energy is transferred as movement 5. Turbine is spun 6. Causing electricity to be generated in the generator |
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How do nuclear fuels release energy? |
Nuclear fuels are not burnt to release energy. Instead, nuclear fission reactions (where the nuclei in atoms are split) in the fuels release heat energy. |
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What is the advantage of nuclear power of fossil fuels? |
Unlike fossil fuels, nuclear fuels do not produce carbon dioxide or sulfur dioxide. |
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What are the disadvantages of nuclear fuels? |
1. Nuclear fuels are non-renewable energy resources. 2. If there is an accident, large amounts of radioactive material could be released into the environment. 3. In addition, nuclear waste remains radioactive and is hazardous to health for thousands of years. |
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How is wind produced? |
The wind is produced as a result of giant convection currents in the Earth's atmosphere, which are driven by heat energy from the sun. |
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Describe how a wind turbine works? |
1. Blades mounted on a tall tower, the wind spins them. 2. The blades are connected to a housing, which contains gears linked to a generator. As the wind blows, it transfers some of its kinetic energy to the blades, which turn and drive the generator. |
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What are the adavtnages of wind power? |
1. Wind is a renewable energy resource 2. There are no fuel costs. 3. No harmful polluting gases are produced. |
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What are the disadvantages of wind power? |
1. Wind farms are noisy 2. They may spoil the view for people living near them. 3. The amount of electricity generated depends on the strength of the wind. If there is no wind, there is no electricity. |
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How is water from the waves transferred into electricity? |
The water in the sea rises and falls because of waves on the surface. Wave machines use the kinetic energy in this movement to drive electricity generators. |
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Describe how the energy from the tides is converted into electricity? |
A tidal barrage is a barrier built over a river estuary to make use of the kinetic energy in the moving water. The barrage contains electricity generators, which are driven by the water rushing through tubes in the barrage. |
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How does hydroelectric power work? |
The water comes from a dam built across a river valley. The water high up behind the dam contains gravitational potential energy. This is transferred to kinetic energy as the water rushes down through tubes inside the dam. The moving water drives electrical generators |
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What are the advantages of hydroelectric power? |
1. It is a renewable energy resource 2. There are no fuel costs. 3. No harmful polluting gases are produced. 4. Tidal barrages and hydroelectric power stations are very reliable and can be easily switched on. |
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What are the disadvantages of hydroelectric power? |
1. Flooding destroys the habitat of animals 3. Hydroelectricity dams flood farmland and push people from their homes. 4. The rotting vegetation underwater releases methane, which is a greenhouse gas. 5. Expensive To build |
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What is geothermal energy? |
Hot water and steam from deep underground can be used to drive turbines: this is called geothermal energy. |
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Describe how Geothermal energy is transferred to electricity in volcanic areas? |
1. Radioactive decay of radioactive substances releases heat energy 2. The Heat energy warms up the rocks around them. 3. The rocks heat water so that it rises to the surface naturally as hot water and steam which can be used to drive turbines and electricity generators. |
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Describe how Geothermal energy is transferred to electricity in NON volcanic areas?
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1. Deep wells can be drilled down to the hot rocks and cold water pumped down. 2. The water runs through fractures in the rocks and is heated up. 3. It returns to the surface as hot water and steam, where its energy can be used to drive turbines and electricity generators. |
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What are the advatnages of Geothermal energy? |
1. Geothermal energy is a renewable energy resource 2. There are no fuel costs. 3. No harmful polluting gases are produced. |
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What are the disadvatnages of Geothermal energy? |
1.Most parts of the world do not have suitable areas where geothermal energy can be exploited. |
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What are solar cells? |
Solar cells are devices that convert light energy directly into electrical energy. |
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What are the advantages of solar cells? |
1. Solar energy is a renewable energy resource and there are no fuel costs. 2. No harmful polluting gases are produced. 3. Solar cells provide electricity in remote locations, such as roadside signs |
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What are the disadvantages of solar cells? |
1. Solar cells are expensive and inefficient, so the cost of their electricity is high. 2. Solar cells do not work at night 3. Grid compatibility 4. Use of precious metals to make them |
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What is the order of power station start up times? |
1. Gas-fired station (shortest start-up time) 2. Oil-fired station 3. Coal-fired station 4. Nuclear power station (longest start-up time). |
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Descrbe coal and nuclear running times, and why? |
Nuclear power stations and coal-fired power stations usually provide 'base load' electricity - they are run all the time because they take the longest time to start up. |
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Describe oil and gas power station running times and why? |
Oil-fired and gas-fired power stations are often used to provide extra electricity at peak times, because they take the least time to start up. |
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Describe the costs of a nuclear power station? |
The fuel for nuclear power stations is relatively cheap, but the power stations themselves are expensive to build. It is also very expensive to dismantle old nuclear power stations and to store their radioactive waste, which is a dangerous health hazard. |
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Why is energy transferred at high voltage through the national grid? |
When a current flows through a wire some energy is lost as heat. The higher the current, the more heat is lost. To reduce these losses, the National Grid transmits electricity at a low current. This needs a high voltage. |
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What is a transformer? (other than a car/robot) |
Transformers are used in the National Grid. A transformer is an electrical device that changes the voltage of an alternating current (ac) supply, such as the mains electrical supply. |
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What is a transformer that increases the voltage called? |
A set up Transformer |
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What is a transformer that decreases the voltage called? |
A set down Transformer
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At what voltage do power stations produce electricity? |
Power stations produce electricity at 25,000 V |
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What are the three voltages that the electricity are sent through the wire at? |
1. 400,000 V 2. 275,000 V 3. 132,000 V |
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Describe why the voltage is needed to be stepped down again before entering peoples homes? |
This reduces energy losses during transmission but the voltages would be dangerous in homes. Step-down transformers are used locally to reduce the voltage to safe levels. |
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What is the voltage of household electricity? |
The voltage of household electricity is about 230 V.
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Describe the electricity route? |
Power stations > step-up transformers > high voltage transmission lines > step-down transformers > consumers, for example homes, factories and shops. |
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What are waves? |
Waves are vibrations that transfer energy from place to place without matter (solid, liquid or gas) being transferred. |
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What is the substance a wave travels through called? |
The substance is known as the medium and it can be solid, liquid or gas |
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What two waves have to travel through a medium? |
Sound waves and seismic waves |
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Give four waves that can travel through empty space? |
1. Visible light 2. Infrared rays 3. Microwaves 4. Other types of electromagnetic radiation |
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Describe the property of oscillations in tranverse waves? |
1. The oscillations (vibrations) are at right angles to the direction of travel and energy transfer |
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Name four types of tranverse waves? |
1. Water waves 2. S waves 3. Light 4. Other types of electromagnetic radiation |
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Draw (with your finger if you like or with your mind or something don't actually be bothered to draw i) a transverse wave? |
Yoohoo here i am.. idk why this picture has gone gothic tho |
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Describe the property of oscillations in longitudal waves?
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1. The oscillations are along the same direction as the direction of travel and energy transfer. |
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Give three types of longitudal waves? |
1. Sound waves 2. Waves in a stretched spring 3. P waves |
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What do longitudal waves show? |
Longitudinal waves show area of compression and rarefaction. |
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Draw a longitudal wave? |
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What is the amplitude and wavelength draw it? |
The amplitude of a wave is its maximum disturbance from its undisturbed position |
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What is the wavelength of a wave? |
The wavelength of a wave is the distance between a point on one wave and the same point on the next wave |
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What is the amplitude of a wave? |
The amplitude of a wave is its maximum disturbance from its undisturbed position |
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What is the frequency of a wave? |
The frequency of a wave is the number of waves produced by a source each second. It is also the number of waves that pass a certain point each second. |
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What are the units of frequency? |
The unit of frequency is the hertz (Hz). It is common for kilohertz (kHz), megahertz (MHz) and gigahertz (GHz) to be used when waves have very high frequencies. |
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What is wave speed measured in? |
m/s |
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What is the wave length measured in? |
Meters |
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When do sound waves and light waves change speed? |
Sound waves and light waves change speed when they pass across the boundary between two substances with different densities, such as air and glass. |
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When dosn't refraction occur? |
Refraction doesn't happen if the waves cross the boundary at an angle of 90° (called the normal) - in that case they carry straight on. |
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What is refraction |
When a wave passes across the boundary between two substances with different densities, such as air and glass. This causes them to change direction and this effect is called refraction. |
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What is diffraction? |
When waves meet a gap in a barrier, they carry on through the gap. However, the waves spread out to some extent into the area beyond the gap. This is called diffraction. |
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In diffraction what does the extent of the spreading of the wavelengths after going through the gap show? |
The extent of the spreading depends on how the width of the gap compares to the wavelength of the waves. |
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In diffraction what does a gap similar to the wavelength cause, and give an example? |
1. A lot of spreading 2. No sharp shadow Example: Sound through a doorway |
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In diffraction what does a gap much larger than the wavelength cause, and give an example?
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1. Little spreading 2. A sharp shadow Example: light through a doorway. |
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Whcih two waves reflect from surfaces? |
Sound waves and light waves reflect from surfaces |
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What is the law of reflection? |
the angle of incidence equals the angle of reflection |
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Describe how you would find the angle of incidence and reflection? |
1. The normal is a line drawn at right angles to the reflector 2. The angle of incidence is between the incident (incoming) ray and the normal 3. The angle of reflection is between the reflected ray and the normal. |
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What materials can form images and how? |
What: Smooth surfaces How:Because The waves are reflected uniformly |
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How can waves appear when reflected off smooth surfaces? |
1. Appear to come from a point behind the mirror 2. Be focused to a point |
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What is the image in a mirror? |
1. Virtual (it cannot be touched or projected onto a screen) 2. Upright (if you stand in front of a mirror, you look the right way up) 3. Laterally inverted (if you stand in front of a mirror, your left side seems to be on the right in the reflection). |
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Describe how the sound of a wave can be changed? |
1. The greater the amplitude, the louder the sound |
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Describe how the pitch of a wave can be changed?
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2. The greater the frequency, the higher the pitch. |
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Which two waves have the same frequency? |
1 and 2 |
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Which wave has the lowest sound? |
Wave 1 |
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Which has the lightest pitch? |
Wave three |
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What is the human range of hearing? |
This is between about 20 Hz and 20 kHz, but the range becomes less as we get older. |
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What aresounds with frequencies above about 20 kHz called? |
Sounds with frequencies above about 20 kHz are called ultrasound. |
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What is the elctromagnetic spectrum? |
The electromagnetic spectrum is a continuous range of wavelengths. |
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What do the types of radiation that occur in different parts of the spectrum depend on? |
The types of radiation that occur in different parts of the spectrum have different uses and dangers, which depend on their wavelength and frequency. |
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How can a spectrum of light be formed? |
White light can be split up using a prism to form a spectrum. |
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Describe how a prism forms a spectrum of light? |
The light waves are refracted as they enter and leave the prism. |
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Describe how the coloured light is refracted? |
The shorter the wavelength of the light, the more it is refracted. As a result, red light is refracted the least and violet light is refracted the most, causing the coloured light to spread out to form a spectrum. |
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What is the order of waves in the elctromagnetic spectrum? |
1. Radio Waves 2. Microwaves 3. Infrared radiation 4. Visible Light 5. Ultra Violet 6. X-rays 7. Gamma Rays |
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What are radio waves used for? |
TV signals |
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What are microwaves used for? |
Cooking and mobile phones |
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What is infared radiation used for? |
optical fibre communication |
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What is visible light used for? |
Seeing |
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What are ultravoilet rays used for? |
Detecting forged bank notes |
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What are X-rays used for? |
Medical images of bones |
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What is gamma raditiaon used for? |
Killing cancer cells
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Which wave has the longest/shortest wave length? |
Longest: Radio Waves Shortest: Gamma Radiation |
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Which wave has the lowest/highest wave frequency? |
Lowest: Radio Waves Highest: Gamma Radiation |
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Which wave has the lowest/highest wave energy? |
Lowest: Radio Waves Highest: Gamma Radiation |
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Which waves can be used for communications? |
1. Radio waves 2. Microwaves 3. Visible light 4. Infrared |
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What are radio waves used to transmit? |
Radio waves are used to transmit television and radio programmes. |
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Why does a program reciever not have to be directly in front of the transmitter? |
Diffraction allows low-frequency radio waves to be received behind hills, although repeater stations are often used to improve the quality of the signals. |
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What is the electrically charged layer of the upper atmosphere called? |
The ionosphere |
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How do the lowest frequency waves reach recievers? |
The lowest frequency radio waves are also reflected from an electrically charged layer of the upper atmosphere, called the ionosphere. This means that they can still reach receivers that are not in the line of sight because of the curvature of the Earth's surface. |
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How do microwave transmitters work? |
Microwave transmitters and receivers on buildings and masts communicate with the mobile telephones in their range. |
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Why do some people think cell phones could be bad for your health and what isits counter argument? |
Mobile phones, which transmit and receive microwaves, may be a health risk. This is not accepted by everyone, as the intensity of the microwaves is too low to damage tissues by heating, and microwaves are not ionising. |
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Describes how microwaves can transmit to sattelites? |
Certain microwave radiation wavelengths pass through the Earth's atmosphere and can be used to transmit information to and from satellites in orbit. Satellite television signals use microwaves. |
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Describe what visible light needs? |
The use of visible light needs the transmitter and receiver to be in the line of sight. |
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Describe how humans notice Infrared radiation? |
We cannot see infrared radiation, but we can feel it as heat energy. High intensity infrared is used in heaters, toasters and grills, and it can cause burns. |
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What are Infrared sensors used in? |
Infrared sensors can detect heat from the body. They are used in: 1. Security lights 2. Burglar alarms. 3. Remote controls |
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Describe the process of the big bang |
The theory states that originally all the matter in the universe was concentrated into a single incredibly tiny point. This began to enlarge rapidly in a hot explosion (called the Big Bang), and it is still expanding today. |
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How long ago did the Big Bang happen? |
The Big Bang happened about 13.7 billion years ago |
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Describe what astronomers have detected that prove the big bang theory? |
Astronomers have even detected a cosmic microwave background radiation, CMBR, that is thought to be the heat left over from the original explosion. |
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What is the doppler effect? |
Where there is a change in frequency and wavelength, is called the Doppler effect. |
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Describe what happens when a police siren moves towards a person and then away again? |
1. Towards an observer: the observed wavelength decreases and the frequency increases. 2. When a source moves away from an observer, the observed wavelength increases and the frequency decreases. |
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How does the spectrum of light show that there is helium in our sun? |
Our Sun contains helium. We know this because there are black lines in the spectrum of the light from the Sun where helium has absorbed light. |
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What do the lines of the spectrum of light represent? |
The absorption spectrum |
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Why do the positions of the lines in the absorbtion spectrum change? |
The positions of the lines have changed because of the Doppler effect. Their wavelengths have increased (and their frequencies have decreased). |
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Describe what effect a star further away from us have and what it shows? |
Astronomers have found that the further from us a star is, the more its light is red-shifted. This tells us that distant galaxies are moving away from us, and that the further away a galaxy is, the faster it's moving away. |
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What does Red shift show? |
Since we cannot assume that we have a special place in the Universe, this is evidence for a generally expanding universe. It suggests that everything is moving away from everything else. |
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What are the rays coming from every direction in space? |
Scientists discovered that there are microwaves coming from every direction in space: this is called the cosmic microwave background radiation, or CMBR for short. |
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Give three things that prove the big bang? |
1. CMBR 2. Red - shift, other galaxies are moving 3. Red shift - everything is moving. Maybe the universe started from a single point? |
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What happens to wasted energy? |
It dissapates into the surrondings |
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How do you go from kilowatts to watts? |
You divide by 1000 |
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Give an environmental advantage to turning off electrical apliances when they are not in use? |
Less fossil fuels are burnt and they are conserved |
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Why is it important to confirm data independently? |
To advoid bias and make sure the results are reproducible |
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Give 4 simmillar properties of radiowaves and microwaves? |
1. They are both transverse waves 2. They can be used for communications 3. They travel at the same speed through air 4. They transfer energy |
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What word must you use when talking about electrons in metals? |
They are free electrons |
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Why is the image seen in a mirror virtual? |
It is a reflection |
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Why does red shift prove evidence for the beginning of the universe? |
1. Started from a single point 2. Galaxies are moving away from each other 3. More distant galaxies show more red shift 4. More distant galaxies are moving away faster |
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What is the origin of CMBR? |
Radiation produced shortly after the big bang |
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How does CMBR prove the big bang theory to be correct? |
1. Can only be explained by the big bang theory 2. Existence predicted the big bang theory 3. Provides further evidence for the big bang theory |
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How will the wavelength of CMBR be likely to change in the next billion years? |
It will increase |
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Why will the wavelength to CMBR increase over the next billion years? |
Universe continues to accelerate outwards and there is greater red shift |
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Sheldons definition of the doppler effect? |
It's the apparent change in the frequency of a wave caused by the relative motion between the source of the wave and the observer. |
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What is a virtual image? |
1. An image that cannot be projected onto a screen 2. Rays of light seem to come from it, but do not pass through it |
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Give examples of infrared waves being used for communication? |
1. Remote controls 2. Data transmission 3. Optic fibre signals |
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Many scientists think that the 'big bang' theory describes the..... |
origins of the universe |
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What is the approximate range of wavelengths of electromagnetic waves? |
10-15 meters to 104 |
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What appliance is most likely to be 100 percent effective? |
A Heater |
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What is wave power? |
The water in the sea rises and falls because of waves on the surface. Wave machines use the kinetic energy in this movement to drive electricity generators. |
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What is the method of wave power that science dude said? |
A column that pushed air up and down as the sea rose and fell and this turns the turbine and generator in the column |
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What are the advantages of wave power? |
1. Its renwebale 2. It does not produce C02 |
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What are the disadvantages of wave power? |
1. Its not reliable as it is weather dependent 2. Noisy which could affect wildlife |
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Where is a tidal barrage built across? |
A river estuary |
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Describe how tidal power is used to generate electricity? |
1. Tidal barrage built across an estuary 2. The barrage is open allowing water to flood in 3. The barrage is closed 4. Water is allowed to rush out through turbines generating electricity |
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Give the advantages of tidal power? |
1. Renewable 2. Does not produce C02 3. Very Reliable 4. Could be used as a bridge |
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Give the disadvantages of tidal power? |
1. Desturtive to wildlife habbitats 2. Difficult and expensive to build |
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Describe the misconception of images in mirrors? |
Although rays of light seem to come from the reflected image they dont actually pass through it |
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Describe the formation of fossil fuels? |
1. Plants and animals and fish died 2. They fell to the bottom of the seabed/earth 3. They were covered by a layer of sand, clay and other minerals 4. The animal remains decomposed 5. Forming fossil fuels |
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Describe what causes variation in fossil fuels? |
Diffeent fossil fuels formed depening on the caombination of organic matter, temperature, time and pressure |
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Why are fossil fuels sought after |
Because they have a high energy density |
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What is Energy? |
Energy is the capacity to do work |
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What is power? |
Power is the rate of doing work |
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What is the difference between energy and power? |
Power is the rate of doing work and energy is the capacity for doing work |
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What is used to harness wave power? |
A special buoy |
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How are tides created? |
Tides are caused by the gravitational forces exerted by the sun the moon and the rotation of the earth |
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What change allows energy to be created from tides? |
The (usually) two tidal changes per day |
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Why does water (turning a turbine) produce more energy than air? |
Because it is of a higher density |
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What is good about tidal power? |
A predictable energy source |
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Describe location and tidal energy? |
It neds specific coastline locarions |
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Why can't tidal energy be used to create all energy? |
The energy made doesn't match consumption rate |
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What do solar cells use to convert sunlight energy directly into solar energy? |
Semiconductors |
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How do semiconductors work? |
Heat hits the semiconductor and electrons are freed forming an electrial current |
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Define renewable energy? |
A group of energy technologies derieved from sources that do not depleate and can be replenished in a humans lifetime. |
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Describe whether nuclear is renewable? |
It is not it is simply an alternative |
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What are the three overall disadvantages of renewable energy sources? |
1. Low efficeincy 2. Costs 3. Intermitancy |
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Describe nuclear fission? |
Fission produces energy through the splitting of atoms which releases heat energy which can be harrnessed to produce electricity |
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Describe nuclear statiosn and greenhouse gasses? |
There are none produced |
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Why is energy from hydropower considered a renewable resource? |
Because of the continous water cycle caused by the sun |
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What is the disadvnatge of using run of rivers? |
Much greater variablity/lack of reliability |
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Describe when land is flooded using hydroelectric power? And the controversial side? |
When the dam breaks Can help with flood control |
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Describe what happens to the products of geothermal energy? 1. Steam 2. Water |
Steam: Used to turn turbines Water: Can be directly pumped into peoples homes for hot water |
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Describe the biggest disadvantage of geothermal energy? |
Can cause an accidental release of Co2 and hydrogen sulfide stored in the earth's groundwater |
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Describe the advantage of natural gas over other fossil fuels? |
Produces less Co2 than other fuels |
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Before carbon dioxide is stored underground, what happens to it? |
It is seperated from other gasses |
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Biggest advantage of renewable resources of fuel? |
Don't cost anything |
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What happens to the medium when waves travel through it (only in waves that need a medium)? |
The medium vibrates |
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When waves that do not need to travel through a medium travel, what vibrates? |
Electrical and magnetic fields vibrate as the waves travel. |
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What causes light and sound waves to chnage speeds? |
Travelling between two different densities |
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What happens when light and sound waves relfect off rough surfaces? |
Rough surfaces scatter sound and light in all directions. |
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When reflecting off rough surfaces what rule is maintained? |
However, each tiny bit of the surface still follows the rule that the angle of incidence equals the angle of reflection. |
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Name two ways which radiowaves can bee transmitted to recievers out of the line of sight? |
Diffraction and relfection of the ionspehere |
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Describe three ways visible light lets us communictae |
It allows us to communicate with one another through books, hand signals and video |
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Describe the disadvantage of an oridanary light? |
Ordinary electric lamps contain a thin metal filament that glows when electricity passes through it. However, most of the electrical energy is transferred as heat energy instead of light energy. |
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Describe the advnatge of LED's? |
Modern energy-saving lamps and LEDs (light-emitting diodes) work in a different way: they transfer a greater proportion of electrical energy as light energy. |
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Describe the difference between LEDs and normal lights |
LEDS use far much more useful energy and less heat, and normal bulbs emit far more heat because of large resistance due to heating of the metal filament |
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What is energy TRANSFERRED measured in when time is in hours and Kilowatts ? |
kWh |
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What is power measured in? |
Watts or Kilowatts |
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What is energy TRANSFERRED measured in when time is in seconds and watts ? |
Joules |
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Describe mice and surface area |
Small animals like mice have a large surface area compared to their volume. They lose heat to their surroundings very quickly and must eat a lot of food to replace the energy lost |
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What is the national gird? |
A series of cables and transformers |
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What do silvered surfaces relfect? |
Infrared radiation |
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What do silver surfaces stop heat loss by? |
Radiation |
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What do small ears do? |
Reduce heat loss via radiation |
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How to reduce co2 in the atmosphere? |
Plant more trees Carbon capture |
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What do short start up time power stations do? |
Meet surges in demand |
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Describe a weird advantage of hydroelectric power stations? |
They can store energy for later |
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When a ray is reflected out of a block it should be..... |
Parrallel to the one going into the block |
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Describe the relationship between the angle of incidence and refraction? |
1. As incidence increases so does refraction 3. Refraction is always less then incidencre |
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Give the Ethical disadvantages to fossil fuels? |
1. Fair access to energy for all 2. Unequal use of energyresources 3. consequences for the futureof decisions made now 4. damage to globalenvironment affects all |
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Give the ethical advantages to fossil fuels? |
1. Creates electricity to power the world |
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Describe three differences betwene visible light and ultraviolent? |
1. Different wavelengths 2. Different frequencies 3. Have different energy levels |
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What does decommision mean? |
To dismantle it and get rid of radioactive waste |
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How can you reduce effect on the environemtn by fossil fuels? |
1. Carbon capture 2. Nuclear power 3. Renewable energy 4. Less fossil fuels |
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Describes the intermolecular forces between particles in a gas? |
They are negligable |
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What is the steady state theory?
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The Steady State Theory suggests that as the universe expands new matter is created, so that the overall appearance of the universe never changes.
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Which has the lowest wavelength? Violet light or red light?
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Violet has a shorter wavelength than red light |
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Which Is refracted most, violet light or red light?
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Violet light because it has a shorter wavelength |
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What is the problem with the big bang theory
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It can't explain why galaxies are in clusters and not evenly spread out
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