One end of a tube is closed, and the other is open. A 15 g projectile is placed near the closed end, is fastened in place with a removable pin, and the space (1 cm3) between the projectile and the sealed end is filled with air and is held at a pressure of 1 MPa and a temperature of 27°C. The ambient air is at 0.1 MPa. Assuming that the air in the closed end expands isothermally when the pin is pulled, and that the pressure of the air inside the tube is 0.1 MPa when the projectile reaches the open end of the tube, find the following: (a) the final volume and the mass of the air at that point, (b) the work done by the air and work done on the atmosphere, and (c) the work to the projectile and the projectile's exit velocity.