Question

A 200 N wagon is to be pulled up a 30 degrees incline at a constant speed. How large a force in kN parallel to the incline is needed if friction effects are negligible?

Answer 1

Let's apply the Newton's Second Law of Motion:

$$F_{pull}-Wsin\theta=0,$$ $$F_{pull}=Wsin\theta=200\ N\times sin30^{\circ}=100\ N=0.1\ kN.$$