24. A crane lifts a 425 kg steel beam vertically a distance of 117m. How much work does the crane do on the beam if the beam accelerates upward at 1.8 m/s2? Neglect frictional forces.
(A) 1.8 x 105 J
(B) 3.4 x 105 J
(C) 4.0 x 105 J
(D) 4.9 x 105 J
(E) 5.8 x 105 J.
阿摩線上測驗
登入