47.2-kg block of ice slides down an incline 1.62 m long and 0.902 m
high. A worker pushes up on the ice parallel to the incline so that it
slides down at constant speed.
The coefficient of kinetic friction between the ice and the incline is 0.110. Find
(a) the force exerted by the worker,
(b) the work done by the worker on the block of ice, and
(c) the work done by gravity on the ice.