One mole of an ideal gas is warmed slowly so that it goes from the PVstate $\left(P_{i}, V_{i}\right)$ to $\left(3 P_{i}, 3 V_{i}\right)$ in such a way that the pressure of the gas is directly proportional to the volume. (a) How much work is done on the gas in the process? (b) How is the temperature of the gas related to its volume during this process?