The engine of a small aircraft (m = 1400 kg including pilot) develops 180 hp. The airplane's speed is increased from 30 m/s to 45 m/s while it climbs from ground level to a height of 500 m in a time of 60 seconds.
(a) What is the power used in changing the kinetic energy?
(b) What is the power used in changing its gravitational potential energy?
(c) What is the efficiency of the airplane?