What is the minimum work needed to push a 850 -kg car 750 m up along a 9.5 ∘ incline? Ignore friction. Express your answer to two significant figures and include the appropriate units.

Answer 1

The change in height h is what matters. With hypotenuse = 750 m and angle 9.5°, the side opposite this angle is h and sin 9.5 = h/750, h = 124 m. The minimum work is the change in potential energy, which is mgh = (850 kg) (9.81 m/s²) (124 m) = 1.0 x 10⁶ Joules.