An aircraft uses a rocket-assisted takeoff unit (RATO) that is capable of discharging 49.0 kg of gas in 15.0 s with an exhaust velocity of 1300 m/s. The 3000 kg aircraft, on an ordinary takeoff without RATO, requires a distance of 440 m to reach a lift-off speed of 210 km/hr with a constant propeller thrust. What is the thrust developed by the rocket?

.With both the RATO and the normal propeller thrust providing a constant acceleration, what is the distance required for lift-off?