A jet airliner moving initially at 733 mph (with respect to the ground) to the east moves into a region where the wind is blowing at 449 mph in a direction 57° north of east. What is the new speed of the aircraft with respect to the ground? Answer in units of mph.

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.