Review the formula changes in energy content equals energy transferred as heat plus energy transferred as work. U = q+ w. Discuss how the energy of the universe is constant, conserved and must be accounted for. Elicit that U = internal energy, which is the sum of potential and kinetic energy. Work is determined by the formula W= -P + delta V, were V is the volume of a gas and P is the pressure. Work is in Joules, pressure in Pascals, and volume change om M^3. Start solving problem on page 269, check your understanding.