# Work and energy - Higher

can be increased by:

• increasing the - this increases the freqency and of collisions
• decreasing the - this increases the frequency of collisions but not the force

A force applied to the particles in a gas causes a transfer of .

When a person presses a piston down on a column of gas, they apply a to move the piston a certain distance.

is done on the gas to compress it:

work done (J) = force (N) Ć distance (m)

Mechanical work transfers energy from the person or machine's store of chemical energy to the store of the gas.

The volume of the gas decreases so the pressure increases. This is because the gas are moving in less space, so they collide with the container walls more often.

The temperature of the gas is not fixed in most applications, and the increased pressure leads to an increase in temperature. Temperature is a measure of the average of particles, so an increase in the energy store of the gas (as kinetic energy of the particles) means that the temperature must increase.

This process explains why a bicycle pump gets warm when it is used to inflate a tyre.