A bicyclist is coasting straight down a hill at a constant speed. The mass of the rider and bicycle is 55.0 kg, and the hill is inclined at 16.0° with respect to the horizontal. Air resistance opposes the motion of the cyclist. Later, the bicyclist climbs the same hill at the same constant speed. How much force (directed parallel to the hill) must be applied to the bicycle in order for the bicyclist to climb the hill?

Answer 1

force friction= forcegravity down hill= mg*SinTheta figure that out.

then, going up the hill, the rider has to over come gravity (same amount) and friction, or force= 2mgSinTheta

Answer 2

56