1. A skier of mass 80 kg starts from rest and slides down a frictionless slope of length 35 m that is inclined at an angle of 30 degrees with the horizontal. Ignore air resistance.
a. Calculate the work done by gravity on the skier, and the work done by the normal force on the skier.
b. If the slope is not frictionless so that the skier has a final velocity of 25 m/s, calculate the work done by gravity, the work done by the normal force, the work done by friction, the force of friction, and the coefficient of kinetic friction.