The document contains 3 solved thermodynamics exercises: 1) Calculating the work done during a tennis match given the heat lost and change in internal energy. 2) Calculating the work done in each reversible process shown on a p-V diagram of a fixed amount of gas. 3) Determining if the change in entropy is positive, zero, or negative when 1 kg of ice melts to water at 0°C, and calculating the change in entropy.