Energy -> Energy Changes in a System Flashcards
(HT) How can doing work on a gas increase its temp? (3 marks)
Work is done to overcome the force caused by the pressure of gas.
Energy is transferred to the gas’s internal store, which raises its temperature.
What 2 factors affect the rate of thermal energy transfer?
- Thermal conductivity
- Thickness of the material
What is thermal conductivity?
The rate at which a material conducts heat
What 2 factors affect the rate of thermal energy transfer?
Thermal conductivity of material,
Thickness of material
What key word do you need when describing specific latent heat?
Thermal energy
Are GAMMA rays highly ionising or highly penetrating?
Highly penetrating
Are isotopes with short or long half-lives chosen for medical uses of radiation?
Short half-lives of a few hours:
- Long enough for the procedure
- however, not so long that they cause long-term harm
How can you increase the efficiency of a thermal energy transfer?
Add thermal insulation.
What are the units for specific heat capacity?
J/kg°C
What is power?
The rate of energy transfer.
What is a closed system?
A system where energy is conserved.
How can you increase the efficiency of a mechanical energy transfer?
By lubricating moving parts, which reduces friction.
What two things affect the size of the elastic potential energy store of a spring?
- Spring constant
- Extension
What is the law of conservation of energy?
Energy cannot be created or destroyed, it can only be transferred between one store and another.
