Key: ☺ = My Answer!
1. The thermal energy of an object is _____.
its potential energy
its average kinetic energy ☺
its potential energy minus its kinetic energy
its kinetic energy plus its potential energy
2. A device that can be used both for cooling and heating is a _____.
heat engine
compressor
heat pump
vaporizer ☺
3. All objects emit _____ radiation.
electromagnetic ☺
kinetic
thermal
solar
4. Fast food restaurants keep food hot with infrared lamps. The heat is transferred to the food by _____.
condensation
conduction
convection
radiation ☺
True or False
5. Air is a good conductor of heat.
true ☺
false
6. When you hold a ball above the ground it has kinetic energy.
true
false ☺
7. A good refrigerant must have a low boiling point.
true ☺
false
6 answers
2. you are right
3. correct
4. thermal radiation you are correct
5. Best is Radiation
Next is Conduction
Last is convection (air) So false
6. An example of potential energy is a ball sitting at the top of a ramp, but not moving. It has potential energy. The same could be said if you just hold a ball above the ground a few inches. Kinetic energy is basically movement energy. When the ball rolls down that ramp, it's potential energy is changed to kinetic (and heat!) energy. Same as when you drop the ball from your hand.
So false
7. A refrigerant must have a low BP because it must be able to release the excess heat. It does that via Boiling. True