We have some gas in a cylinder. The diameter of the cylinder is 8.1 cm. The mass of the piston is 13.5 kg. The atmospheric pressure is 9.4 x 10^4 Pa. (a) Find the pressure (Pa) of the gas. (Both the weight of the piston and the pressure of the atmosphere on top of the piston contribute to the pressure of the gas inside the cylinder.) (b) If we heat up the gas so that the piston rises from a height of 12.3 cm to 15.6 cm (measured from the bottom of the cylinder), find the work (J) done on the gas. Note that the pressure of the gas remains constant as it is heated up. Be sure to include the correct sign on the answer.