To move a refrigerator of mass 150 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 7.8 m long and rises 3.3 m. The mover pulls the dolly with constant velocity and with a steady force 1500 N up the ramp. a)How much work does he perform? The acceleration of gravity is 9.8 m/s. Answer in units of J.
b)What is the minimal work required to lift the refrigerator into the house? Answer in units of J.