A spacecraft cruising in space at a constant velocity of 2000 ft/s has a mass of 25,000 lbm. To slow down the spacecraft, a solid fuel rocket is fired, and the combustion gases leave the rocket at a constant rate of 150 lbm/s at a velocity of 5000 ft/s in the same direction as the spacecraft for a period of 5 s. Assuming the mass of the spacecraft remains constant, determine

(a) The deceleration of the spacecraft during this 5-s period,

(b) The change in velocity of the spacecraft during this time period,

(c) The thrust exerted on the spacecraft.