Z. An ideal monatomic gas of N particles, each of mass m, is in thermal equilibrium at absolute temperature T. The gas is contained in a cubical box of side length L, whose top and bottom sides are parallel to Earth's surface. The effect of Earth's uniform gravitational field on the particles should be considered, the acceleration due to gravity being g. (a) What is the average kinetic energy ofa particle? (b) What is the average potential energy of a particle