If the line on a distance-versus-time graph and the line on a speed-versus-time graph are both straight lines going through the origin, can the two graphs be displaying the motion of the same object? Explain.

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.