THERMAL PHYSICS Flashcards
What is internal energy made up of?
Kinetic Energy (Thermal Energy) +
Potential Energy
Define Specific Heat Capacity ,c,
The amount of energy required to raise the temperature of 1 kg of material by 1 Kelvin without a change of state.
Define Latent Heat of Fusion.
The amount of energy required to change the state of 1kg of material, solid to liquid, without a change in temperature.
Define Latent Heat of Vapourisation.
The amount of energy required to change the state of 1 kg of material, liquid to gas, without a change in temperature.
Describe the energy changes for Latent Heat.
When materials change state energy supplied to break the bonds.
This goes to increasing the potential energy, not thermal energy (this is as temperature doesnt increase but temp depends on the thermal energy.)
Why is it better to use ice to cool drinks rather than cold water?
Thermal energy is removed from drinks (it getting cooler) provided they are in something cooler.
Ice better as:
Takes a lot of energy to melt ice (high specific latent heat)
Remains at 0 degrees Celsius as it melts so stays cooler for longer.
Describe properties of Boyle’s Law.
For if temperature of an ideal gas is constant.
Pressure inversely proportional to Volume.
Describe the properties of Charle’s Law.
If pressure of ideal gas constant then:
Volume is proportional to Temperature.
Describe properties of Pressure Law.
If volume of ideal gas is constant:
Pressure is directly proportional to temperature.
Give the two different ideal gas equations.
PV = nRT
or
PV = NkT
If amount of gas remains constant.
P1V1/T1 = P2V2/T2
If temp and amount of gas constant
P1V1 = P2V2
If pressure and amount of gas constant.
V1/T1 = V2/T2
If volume and amount of gas constant.
P1/T1 = P2/T2
State three assumptions for An Ideal Gas.
All collisions elastic.
All molecules identical and move randomly.
Time spend colliding negligible compared to time between collisions.
