I have no idea on how to do either part of these questions please help
(part 1 of 2)
To move a refrigerator of mass 110 kg into a house, a mover puts it on a dolly and covers the steps leading into the house with a wooden plank acting as a ramp. The plank is 8.8 m long and rises 3.6 m. The mover pulls the dolly with constant velocity and with a steady force 730 N up the ramp. How much work does he perform? The acceleration of gravity is 9.8 m/s2 . Answer in units of J.
(part 2 of 2)
What is the minimal work required to lift the refrigerator into the house? Answer in units
of J.
730 N * 8.8 m = 6424 Joules
m g h = 110 * 9.8 * 3.6 = 3880 Joules
by the way the efficiency = 3880/6424 = .604 = 60.4 %