Question

In the figure here, a block of ice slides down a frictionless ramp at angle θ=59.0 ˚ while an ice worker pulls on the block (via a rope) with a force that has a magnitude of 52.0 N and is directed up the ramp. As the block slides down through distance d = 0.500 m along the ramp, its kinetic energy increases by 84.0 J. How much greater would its kinetic energy have been if the rope had not been attached to the block?

Answer 1

Applying the Energy conservation theorem, we have:

$$\Delta K=W_{ext}=Fd\cos{\theta}\\\Delta K=(52)(0.5)=26\ J$$