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113 Cards in this Set

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What is the scientific defintion of energy?
The ability to do work
Lesson 1
What are the eight types of energy recognized by scientists?
Mechanical, chemical, nuclear, thermal, electrical, magnetic, sound, and light
Lesson 1
Which types of energy can be converted into other types of energy?
Pretty much all forms can be converted, although it is unlikely to convert most forms of energy into nuclear energy.
Lesson 1
What is mechanical energy?
The energy of moving objects
Lesson 2
What are the two forms of mechanical energy?
Kinetic and potential
Lesson 2
What are some forces in nature that possess mechanical energy?
Wind, waves, volcano, animals, any object that is higher than ground level, anything that is moving
Lesson 2
What is chemical energy?
Energy that is stored in the bonds of molecules
Lesson 3
What two complementary processes were designed by God to change the sun's energy into energy for all living things?
Photosynthesis and digestion/cellular respiration
Lesson 3
Name two fossil fuels.
Petroleum/oil, coal, and natural gas.
Lesson 3
Other than digestion, what is the most common way to release chemical energy?
Through combustion or burning
Lesson 3
What is nuclear power?
Energy that is released when the nucleus of an atom is changed.
Lesson 4
What is nuclear fission?
A nucleus splits apart after being hit by a speeding neutron.
Lesson 4
What is nuclear fusion?
When a new nucleus is formed by the fusing of two or more smaller nuclei or nuclear particles such as protons and neutrons.
Lesson 4
Which nuclear process is used in nuclear power plants?
Nuclear fission
Lesson 4
What are the two types of nuclear weapons that have been developed?
Fission and fusion
Lesson 5
Why are fusion bombs sometimes called hydrogen bombs?
Energy is released as hydrogen atoms fuse to form helium.
Lesson 5
Why are fusion bombs sometimes called thermonuclear weapons?
The fusion reaction occurs at very high temperatures.
Lesson 5
How are the high temperatures needed for a fusion reaction achieved in a hydrogen bomb?
A small fission reaction is used to produce the temperatures.
Lesson 5
What is thermal energy?
The total energy in an item due to the movement of the item's molecules.
Lesson 6
What is temperature?
The average energy the molecules contain.
Lesson 6
What is a calorie?
The amount of energy needed to raise 1 gram of water 1 degree Celsius.
Lesson 6
How are Calories in food related to thermal energy?
The number of Calories the food contains is the potential energy stored in the food. This represents the amount of thermal energy it can supply.
Lesson 6
What is conduction?
The transferring of heat energy by the collision of faster molecules with slower molecules.
Lesson 7
What is equilibrium?
When two substances have transferred energy until they are both at the same temperature--they both have the same average thermal energy.
Lesson 7
Which materials are good conductors of heat?
Metals are good conductors of heat, and silver is the best conductor.
Lesson 7
What is convection?
The movement of heat by currents
Lesson 8
What causes convection?
Gravity causes denser materials to sink below lighter materials.
Lesson 8
How does convection affect the weather on earth?
Heat from the sun causes convection currents in the air, resulting in winds and movement of weather systems.
Lesson 8
What is thermal radiation?
It is heat that is transferred by way of electromagnetic waves.
Lesson 9
Which type of electromagnetic waves most easily transfer heat energy?
Infrared waves
Lesson 9
Which colors best absorb radiated heat?
Dark colors, especially black.
Lesson 9
What is solar energy?
Energy from the sun.
Lesson 10
What is geothermal energy?
Heat energy from beneath the surface of the earth.
Lesson 10
How is solar energy used?
The radiation is used to heat water in solar panels for use in the home. Also, solar energy can be used to generate electricity.
Lesson 10
How is geothermal energy used?
The heat from the earth is used to generate steam.
Lesson 10
What is electricity?
The flow of electrons.
Lesson 11
What is static electricity?
An electrical charge that is built up on an object.
Lesson 11
What is the Law of Charges?
Opposite charges attract, like charges repel.
Lesson 11
What is an electrical conductor?
A material that easily allows electrons to flow.
Lesson 12
What is an electrical insulator?
A material that does not conduct electricity easily.
Lesson 12
What is a semi-conductor?
A material that allows a small amount of electricity to flow through it.
Lesson 12
What materials are good conductors of electricity?
Metals
Lesson 12
What materials are good electrical insulators?
Wood, plastic, rubber, cloth, etc.
Lesson 12
What is lightning?
A sudden discharge of electricity.
Lesson 13
What causes lightning?
Friction between rapidly moving air, water drops, ice and hail strips electrons from the particles causing clouds to build up a static charge.
Lesson 13
What is thunder?
The sound generated by rapidly expanding air in a thunderstorm.
Lesson 13
What causes the air molecules to move quickly enough to generate thunder?
The enormous amount of heat generated by the flow of electrons in a lightning bolt.
Lesson 13
What is current?
A continuous flow of electrons.
Lesson 14
Name two ways to generate current.
Chemical reaction such as with a battery, with an electromagnet like at a power plant, or with lightning.
Lesson 14
What is a circuit?
It is a complete path or circle through which current can flow.
Lesson 14
What is a short circuit?
When current finds a shorter path back to its source without going through the intended device.
Lesson 14
What is voltage?
It is a measure of the electrical potential energy that can be supplied by a battery or other power source.
Lesson 15
What direction does current flow in a battery?
It flows from the negative terminal to the positive terminal.
Lesson 15
Describe the difference between a serial circuit and a parallel circuit.
A serial circuit has only one path for the current to flow through; a parallel circuit has multiple paths for the current to flow through.
Lesson 16
What is a magnet?
A material in which most of the atoms are lined up in the same magnetic orientation.
Lesson 17
Is the strength of a magnet the same throughout the magnet?
No, the field is strongest near the poles.
Lesson 17
What is the Law of Magnetic Poles?
Opposite magnetic poles attract and same poles repel.
Lesson 17
What materials are magnetic?
Iron, cobalt, nickel, gadolinium, and alloys with these materials.
Lesson 18
How can a magnet lose its magnetism?
A sharp blow can cause the atoms to become randomly aligned and thus lose the magnetic field.
Lesson 18
Do all magnetic materials produce the same strength magnetic field?
No, some magnets are stronger than others.
Lesson 18
How is the earth like a giant magnet?
It has a magnetic field with a north and south pole.
Lesson 19
How far does the earth's magnetic field extend?
It goes several hundred miles into space.
Lesson 19
Where is the earth's magnetic north pole?
It is in the Arctic Ocean north of Canada and south of the geographic North Pole.
Lesson 19
What is an electromagnet?
A magnetic field that is generated when a current passes through a coil that surrounds a magnetic material.
Lesson 20
What are some common uses for electromagnets?
Sorting metals, moving magnetic materials, maglev trains, computer disks, video tapes.
Lesson 20
What is an electric generator?
A device that produces electricity.
Lesson 21
How do most electric generators work?
They use steam to turn a turbine attached to a wire coil that is suspended in a magnetic field. The moving coil creates a changing magnetic field, which induces a current to flow in a nearby wire.
Lesson 21
What is an electric motor?
A device that changes electricity into mechanical energy.
Lesson 21
How does an electric motor work?
A changing current flows through a coil that is suspended in a magnetic field. This creates a changing feild that repels the coil and makes it spin, thus producing mechanical energy.
Lesson 21
What are two different types of energy waves?
Mechanical and electromagnetic, or light and sound.
Lesson 22
What is the main difference between mechanical and electromagnetic waves?
Mechanical waves must have a medium to transport them and electromagnetic waves can move through a vacuum.
Lesson 22
What is the highest point of a wave called?
The peak or crest
Lesson 22
What is the lowest part of a wave called?
Thr trough.
Lesson 22
How is a wavelength of a wave defined?
The distance from one peak to the next peak.
Lesson 22
What characteristic of an electromagnetic wave determines its visible color?
Its frequency or wavelength.
Lesson 23
Which waves have a higher frequency, radio waves or gamma rays?
Gamma rays
Lesson 23
Which kinds of electromagnetic waves are used for communication?
Primarily radio waves, but some communications use microwaves.
Lesson 23
What is a sound wave?
An energy wave that is detectable by the human ear.
Lesson 24
How do sound waves move through the air?
By causing the air molecules to compress and expand as the wave passes through.
Lesson 24
List some materials through which sound waves can travel.
Air, water, metal, wood, the ground, and many other items...
Lesson 24
What types of materials absorb sound waves?
Cloth and other porous materials--materials with many holes in them.
Lesson 24
What are the three main characteristics that determine the quality of a sound?
Pitch or frequency, loudness or amplitude, and overtones or harmonics.
Lesson 25
How does the pitch change as the frequency goes up?
The pitch goes up--gets higher.
Lesson 25
What is an overtone?
It is a secondary wave traveling with the primary wave that has a frequency that is a multiple of the primary frequency.
Lesson 25
What units are used to measure loudness?
Bels or decibles.
Lesson 25
What are acoustics?
A building's effects on sound.
Lesson 26
What is resonance?
When one vibrating material transfers its energy to another material with the same natural frequency.
Lesson 26
What is the Doppler effect?
The pitch of an object increases as the source approaches and decreases as it goes away from you.
Lesson 26
What makes music different from noise?
The notes are distinct. They have specific pitches and timing. Music has rhythm.
Lesson 27
What are the four main types of instruments? How does each make a tone?
Strings--a string is vibrated
Percussion--a surface vibrates when struck
wind--air is made to vibrate by blowing
electronic--vibrations are converted into electrical signals that are amplified and turned into sound waves
Lesson 27
How is a light wave different from a sound wave?
It is at a higher frequency and can travel through a vacuum. It is electromagnetic, not mechanical.
Lesson 28
Name three sources of light.
The sun, flames, light bulbs, etc...
Lesson 28
What color of light has the lowest frequency? What color has the highest frequency?
REd has the lowest frequency and violet has the highest frequency.
Lesson 28
Explain how an incandescent bulb produces light.
It contains a thin wire made of a material (like tungsten) that glows when a current passes through it.
Lesson 28
Explain how a fluorescent bulb produces light.
Electricity excites the gas inside, turning it into plasma. The plasma emits ultraviolet light that causes the phosphor inside the bulb to glow.
Lesson 28
What is the true color of white light?
It contains all colors of visible light.
Lesson 29
Why does light split when it goes through glass or water?
Different colors of light travel at different speeds through different materials, so the rays of light are bent different amounts as they pass through water/glass/etc.
Lesson 29
How do our eyes detect light?
Special cells called rods and cones detect light and send signals to the brain.
Lesson 29
What color of light does a yellow object absorb?
All wavelengths except yellow.
Lesson 29
What is a reflection?
Light that bounces off of a surface.
Lesson 30
Which types of materials best reflect light?
Smooth and shiny materials.
Lesson 30
What kind of path does light take?
It moves in waves that travel in straight lines.
Lesson 30
What are the three shapes of mirrors?
Plane or flat, concave, and convex.
Lesson 31
How does a concave mirror affect light rays and the reflected image?
It bends the light inward and inverts the image (turns it upside-down).
Lesson 31
How does a convex mirror affect the light rays and the reflected image?
It bends the light outward and stretched the image.
Lesson 31
What is refraction?
The bending of light as it changes speeds going from one medium to another.
Lesson 32
Why do items appear to be in a different location underwater than they actually are?
The bent light hits your eyes in a location other than where you expect, making the object appear to be in a slightly different location.
Lesson 32
What is a mirage?
It is a reflection of the sky above the pavement on a hot day. It occurs because light is bent as it moves from denser cooler air into warmer less dense air near the ground.
Lesson 32
What is a lens?
A curved piece of glass or plastic that bends light.
Lesson 33
What effect does a convex lens have on light?
Parallel light rays are bent toward the center of the lens. Images are either upside down and smaller than the actual object, or right side up and larger, depending on the distance from the lens and the lens's focal length.
Lesson 33
What is another name for a concave lens?
Diverging lens.
Lesson 33
Name three inventions that use lenses.
Telescope, microscope, camera, eyeglasses, magnifying glass (and others)
Lesson 33
What effect does a concave lens have on light?
Parallel light rays are bent outward from the lens. The image will be right-side-up and smaller.
Lesson 33