Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
31 Cards in this Set
- Front
- Back
|
Thermal conductors |
Materials that allow thermal energy to move through them easily. E.g Metals |
|
|
Thermal Insulators |
Materials that do not allow thermal energy to move through them easily. Fibreglass - traps air Wood |
|
|
The rate of thermal energy transfer through a material depends on: |
- the temp difference across the material - the thickness of the material - the thermal conductivity of the material |
|
|
To reduce the rate of thermal energy transfer, the material should: |
- have as low thermal conductivity as possible - be as thick as possible |
|
|
Practical: Testing sheets of materials as insulators |
1) Add an insulating material onto a beaker and pour boiling water in it 2) Record the starting temp 3) Record The temp every 10 seconds for a fixed period of time 4) Repeat for different insulating materials and compare your results |
|
|
Practical: Testing sheets of materials as insulators - Method |
1) Add an insulating material onto a beaker and pour boiling water in it 2) Record the starting temp 3) Record The temp every 10 seconds for a fixed period of time 4) Repeat for different insulating materials and compare your results |
|
|
Practical: Testing sheets of materials as insulators - Variables |
Control - amount of water, temperature of water, amount of insulating material, size of beaker, outside temperature Independent - The insulating material Dependant - The temperature change |
|
|
Practical: Testing sheets of materials as insulators - Variables |
Control - amount of water, temperature of water, amount of insulating material, size of beaker, outside temperature Independent - The insulating material Dependant - The temperature change |
|
|
Infrared Radiation |
Infrared waves are part of the electromagnetic spectrum. Wavelengths a little more than red light. All objects emit and absorb infrared radiation |
|
|
The temperature of a body increases.... |
If a body absorbs infrared radiation at a greater rate than it emits it. |
|
|
The temperature of a body increases.... |
If a body absorbs infrared radiation at a greater rate than it emits it. |
|
|
The temperature of the body decreases.... |
If a body absorbs infrared radiation at a lesser rate than it emits it. |
|
|
Black Body |
A black body is the best emitter and absorber of infrared radiation. Does not reflect or transmit any infrared waves. Black body radiation is the radiation emitted from black body Perfect black body emits and absorbs all the radiation |
|
|
A body at a constant temperature.... |
Absorbs and emits infrared radiation at the same rate and emits radiation across a continuous range of wavelengths. |
|
|
The intensity of ________ an object_________has a peak at certain_________. This peak __________depends on the_________of the object. |
The intensity of the radiation an object emits had a peak at a certain wavelength. This peak wavelength depends on the temperature of the object. |
|
|
The temperature of the Earth depends on: |
- the rates of absorption and emission of radiation by the Earth’s surface or atmosphere - reflection of radiation into space |
|
|
The temperature of the Earth depends on: |
- the rates of absorption and emission of radiation by the Earth’s surface or atmosphere - reflection of radiation into space |
|
|
Light, shiny surfaces |
Do not absorb and emit radiation at a large rate. Reflect and transmit infrared radiation |
|
|
Specific Heat Capacity |
The amount of energy required to raise the temperature of 1kg of a substance by 1degrees Celsius. |
|
|
Change in Energy = mass x specific heat capacity x _________ ΔE = m x c x _____ |
Change in Energy = mass x specific heat capacity x change in temperature ΔE = m x c x Δθ Joules = kg x J/kg°C |
|
|
Practical: Measuring specific heat capacity |
1) Meausre the mass of the metal block using a balance 2) Connect the Joulemeter to the heater and place the heater into the metal block. 3) Place a thermometer in the other hole 4) Record the start temp of the metal block and switch on the Joulemeter. 5) Wait until the metal block has risen by 10°C and stop the Joulemeter. 6) Record the energy on the Joulemeter and work out the SHC |
|
|
Practical: Measuring specific heat capacity |
1) Meausre the mass of the metal block using a balance 2) Connect the Joulemeter to the heater and place the heater into the metal block and place a thermometer in the other hole 4) Record the start temp of the metal block and switch on the Joulemeter. 5) Wait until the metal block has risen by 10°C and stop the Joulemeter. 6) Record the energy on the Joulemeter and work out the SHC |
|
|
Practical: Measuring specific heat capacity |
1) Meausre the mass of the metal block using a balance 2) Connect the Joulemeter to the heater and place the heater into the metal block and place a thermometer in the other hole 4) Record the start temp of the metal block and switch on the Joulemeter. 5) Wait until the metal block has risen by 10°C and stop the Joulemeter. Record the energy on the Joulemeter and work out the SHC |
|
|
Practical: Measuring specific heat capacity |
1) Measure the mass of the block using a balance, then connect the Joulemeter to the heater and place the heater into the metal block and place a thermometer in the other hole. 2) Record the start temp of the metal block and switch on the Joulemeter. 3) Wait until the metal block has risen by 10°C and stop the Joulemeter. Record the energy on the Joulemeter and work out the SHC |
|
|
How does Loft Insulation help insulate buildings? |
- Has low thermal conductivity - Reduce of the rate of energy transferred out the house - reduces energy transferred through the roof |
|
|
How does Cavity Wall Insulation help insulate buildings |
- contains an internal and external breeze block wall separate by a cavity which has a low thermal conductivity (insulating material). - reduces the rate of energy transferred through the outer walls |
|
|
How does Aliminium Foil behind radiators help insulate buildings? |
- Aluminium foil has a low thermal conductivity - Reflects infrared radiation back into the room |
|
|
How does Double Glazed windows help to insulate buildings? |
Single glazed windows have a thermal conductivity but with double the cover less heat escaped. |
|
|
Why is good to have your houses insulated? |
So that less heat escapes during winter and cold times. Saves money |
|
|
Why is good to have your houses insulated? |
So that less heat escapes during winter and cold times. Saves money |
|
|
Why is using solar panels good? |
Because it saves money because it heats water directly and gets energy from the sun so no electricity is used. |
