Chapter 21
Kinetic Theory of Gases (Lecture Examples)
Example 1: During a storm 500 hailstones strike a 2 m2 window in one minute. If the collisions are
elastic and the hail strikes at a 45° angle what is the pressure exerted on the window? The
average hailstone has a mass of 30 grams and a speed of 40 m/s.
Example 2: Find the rms speed of a hydrogen nucleus at a temperature of 20 million °C.
Example 3: Calculate the change in heat when the temperature of 3 moles of monatomic gas is
doubled at constant volume. The gas is initially at STP.
Example 4: Calculate the change in heat when the temperature of 3 moles of monatomic gas is
doubled at a constant pressure. The gas is initially at STP.
Example 5: 2 moles of a monatomic gas initially at 20 °C and one atmosphere expand adiabatically
to 4 times their initial volume. Find the final volume, temperature and pressure.
Example 6: Calculate the work done by a gas during an adiabatic change.