A box of mass m is initially at rest at the top of a ramp that is at an angle θ with the horizontal. The
block is at a height h and length L from the bottom
of the ramp. The block is released and slides
down the ramp. The coefficient of kinetic friction
between the block and the ramp is μ. What is the
kinetic energy of the box at the bottom of the
ramp?
a) mgh
b) μmgLcosθ
c) mgh - μmgLcosθ
d) mgL - μmghcosθ