Physics Friction Problem

Question

An 84.7 cross country skier on snow has a coefficient of friction = 0.131. With how much force must he push to move at constant speed?

Answer 1

Constant speed (should be velocity) implies a=0 if not turning. Therefore F_net=0 and the friction sliding force must be equal to the force of propulsion (which, by the way, is a static friction force) Therefore,

mgμ = F (84.7 kg)(9.8 N/kg)(.131) = Newtons