P2 Flashcards
How does temperature difference between an object and its surroundings affect the rate at which energy can be transferred?
The greater the temperature difference, the faster the rate of energy transfer
Why are materials that trap air better thermal insulators?
The air is trapped, so air cannot circulate and form convection currents
Will a hotter object emit more or less infrared radiation?
More
What is black body radiation?
The radiation emitted by a body that absorbs all radiation that hits hit
If an object is kept at a constant temperature, what will happen to the rates at which infrared radiation is emitted and absorbed?
The radiation will be emitted and absorbed at the same rate
If an object absorbs infrared radiation at a greater rate than is emitted, the temperature of the object will….
Increase
Which surfaces are the best absorbers of infrared radiation?
Surfaces that are dark and matt
How would you go about measuring the specific heat capacity of a block of aluminium?
1) Measure the mass of the block in kilograms with a balance and record it
2) Place the block inside an insulative material
3) Place a heater and a thermometer inside the block
4) Record the initial temperature in degrees celsius
5) Attach the heater to a joulemeter, and the joulemeter to a power supply
6) Turn on the heater and wait until the temperature has risen by about 10 degrees
7) Record the final temperature and calculate the change in temperature by subtracting your initial reading from your final reading
8) Record the energy supplied to the block in joules.
9) In order to calculate the specific heat capacity, it is necessary to rearrange the equation: (c)E = mc(c)t, so that specific heat capacity is the subject- c= (c)E/(m(c)t)
10) Substitute the values into the equation, and you will get the specific heat capacity in joules per kilogram degrees
