Question

A cyclist on his bike with a total mass of 75 kilograms keeps a constant speed on an inclination of 20 degrees with the horizontal. The bicycle experiences a constant frictional force of 100 Newton over a distance of 40 meters in 15 seconds. Calculate the work done by the force applied to the cyclist

Answer 1

Since the cyclist keeps a constant speed, the net force acting on it es equal to 0. Thus, the total work is equal to 0. Considering only the work due to frictional force, obtain:

$$A = Fs$$

where $F = 100N$ is the frictional force and $s = 40m$.

$$A = 100\cdot 40 = 400J$$

Answer. 0J or 400J depending on what is asked to found.