A crane lifts a 425 kg steel beam vertically upward a distance of 66 m. How much work does the crane do on the beam if the beam accelerates upward at 1.8 m/s2

Question

A crane lifts a 425 kg steel beam vertically upward a distance of 66 m. How much work does the crane do on the beam if the beam accelerates upward at 1.8 m/s2
 Neglect frictional forces.

oobleck · Answer

work = PE gained = mgh