An airplane of mass 1.50 x 10^4 kilogram is moving at 60.0 m/s. The pilot then increases the engine's thrust to 7.50 x 10^4 N. The resistive force exerted by air on the airplane has a magnitude of 4.00 x 10^4N.
(a) Find is the work done by the engine on the plane equal to the change in the plane's kinetic energy after it travels through some distance through the air? Find is mechanical energy conserved? Explain.
(b) Calculate the speed of the plane after it as traveled 5.00 x 10^2 meter. Suppose the plane is in level flight throughout the motion.