Question

You pull a sled across a horizontal frictionless patch of snow. If your pulling force is in the same direction as the sled's displacement and increases the kinetic energy of the sled by 34%, by what percentage would the sled's kinetic energy increase if the pulling force acted at an angle of 42° above the horizontal?

Answer 1

W1 = F s = ∆KE = 0.34KE0

W2 = (F cos 42◦)s = F s cos 42◦ = 0.34∆KE0 cos 42◦ = 0.25∆KE0

Therefore, there is an 25% increase in kinetic energy.