A Level Pearson Edexcel Physics Topic 9 Thermodynamics

Define what is meant by the internal energy of a body

The sum of potential energy contained within the inter-atomic bonds

Define temperature

Is directly related to the mean, random, kinetic energy of the vibrating atoms of a body

Define potential energy

The stored energy

Define kinetic energy

A form of energy that an object or a particle has by reason of its motion

Define heating

The process by which energy is transferred by conduction

Define radiation

The emission or transmission of energy in the form of waves or particles through space or a material medium

Define conduction

The transfer of energy in the form of heat or electricity from one atom to another in an object due to direct contact

Define convection

Process by which heat is transferred by movement of a heated fluid such as air or water.

Formula for energy required to change the temperature of a substance

Where:

c is the specific heat capacity

delta theta is the change in tempreture

Formula for the amount of energy required to change the state of a substance

Where:

L is the specific latent heat

Define specific heat capacity (c)

It is the amount of energy required to increase the temperature of 1kg of the substance by 1 degrees Celsius/1 Kelvin, without changing its state

Define specific latent heat capacity (L)

Is the amount of energy required to change the state of 1kg of material, without changing its state

What are the two kinds of specific latent heat

• Specific latent heat of fusion

• Specific latent heat of vaporisation

What is the specific latent heat of fusion

When a solid changes to liquid

What is the specific latent heat of vaporisation

When liquid changes to gas

Define internal energy

Of a body is equal to the sum of all of the kinetic energies and potential energies of all its particles.

Kinetic and potential energies of a body are randomly distributed.

True or False | Is the kinetic and potential energy of a body are randomly distributed

True, the kinetic and potential energy of a body are randomly distributed

Define Absolute zero

The lowest possible temperature and is the temperature at which particles have no kinetic energy and the volume and pressure of gas are zero

What is the number of absolute zero (so temperate in degrees and kelvin)

-273 Degrees Celsius or 0 Kelvin

How does average kinetic energy of molecules relate to the absolute temperature

Average kinetic energy of molecules in a substance is directly proportional to the absolute temperature of the substance

Kelvin formula

Kelvin and degrees Celsius graph

Define what is an ideal gas

In an ideal gas:

• All interactions are perfectly elastic collisions meaning no intermolecular forces

• Has no potential energy meaning its internal energy is equal to the sum of the kinetic energies of all its particles

Derive this equation