Question

A bicyclist is coasting straight down a hill at a constant speed the mass of the rider and bicycle is 80.0 kg and the hill is inclined 15.0 degrees 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

The diagram looks like this. It's at a constant speed so the net-force is 0.

Answer 2

Sorry I forgot to put the normal force on the top.

Anyways tilt your head to the right a little bit and look at this

Answer 3

I basically divided the Gravity force into components.

The magnitude of the 'down' component of gravity = the magnitude of the 'normal' force.

The magnitude of the 'right' component of gravity = the magnitude of the 'push' force.


You're given angle 15 and here's how it'll fit in the triangle below.


You can use sin or cosine or anything with pythagorean theorem to figure out the missing sides of the triangle.