Module 3: Thermal Physics

Question 1

Pressure

Answer 1

Force per unit area.

Question 2

Internal energy

Answer 2

The sum of the random distribution of kinetic and potential energies associated with the molecules of a system.

Question 3

Absolute zero

Answer 3

The temperature at which a substance has minimum internal energy.

Question 4

Specific heat capacity

Answer 4

The specific heat capacity of a substance is the energy required per unit mass of the substance to raise the temperature by 1K (or 1°C)

Question 5

Boyle’s law

Answer 5

The pressure exerted by a fixed mass of gas is inversely proportional to its volume, provided the temperature of the gas remains constant.

Question 6

The basic assumptions of the kinetic theory of gases

Answer 6

A gas contains a very large number of spherical particles (atoms or molecules)
The forces between particles are negligible, except during collisions.
The volume of the particles is negligible compared to the volume occupied by the gas.
Most of the time, a particle moves in a straight line at a constant velocity. The time of collision with each other or with the container walls is negligible compared with the time between collisions.
The collisions of particles with each other and with the container are perfectly elastic, so that no kinetic energy is lost.