Internal energy & Temperature Flashcards
The internal energy of an object is:
The sum of the random distribution of the kinetic and potential energy of its molecules.
The thermal energy of the object:
- Is dependent on the kinetic energy of the molecules
- Which depends on the temperature of the object
- The hotter they are the faster the vibrate.
The potential energy of the molecules:
- Depends how far away from each other they are
- Is greater in a liquid than in a solid.
What is temperature?
A measure of the degree of hotness of an object.
Defined in terms of ‘fixed points’
Celsius scale measured in °C has:
ice point at 0 °C and steam point at 100 °C at atmospheric pressure.
What is the triple point of water?
The temperature at which ice, water and water vapour are in thermal equilbrium
273.16 K
The first law of thermodynamics says:
Change in internal energy of object = total energy transfer due to work done and heating
Energy transfer takes place between two objects if:
- One object does work on the other one
- One object is hotter than the other one.
What is thermal equilibrium?
When no overall heat transfer occurs between two objects at the same temperature.
What is absolute zero?
The lowest possible temperature, the temperature at which an object has minimum internal energy.
Kelvin to celsius
K - 273.15
Celsius to Kelvin
°C + 273.15
