a hoist powered by a 10kW motor is used to raise a bucket filled with concrete and having a total mass of 500kg to a height of 80m in 50s. what is the efficiency of the hoist?im practicing for exams and i stumbled on this one
10 kW * 50 s = 500 kJ 500 kg * 80 m * 9.8 N = 392 kJ The hoist is 392 kJ/500 kJ * 100 % = 78.4% efficient (78% if we're sticking to significant figures).
