A bicyclist is coasting straight down a hill at a constant speed. The mass of the rider and bicycle is 60.0 kg, and the hill is inclined at 19.0° 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? I am so lost with this one and have no idea where to start.