Energy loss and inclined planes

1. Jun 2, 2013

Dongorgon

1. The problem statement, all variables and given/known data

A trolley is of mass 20kg is pushed 35 metres up an inclined plane (to a height of 10m above ground level). The inclined plane is at arcsin(2/7) to the horizontal. A 100N force pushes the trolley to the top of the plane, the force being parallel to the inclined plane. The work done by the force in pushing the trolley to this point is 3500J and the potential energy 35m up the slope is 1960J. No friction is present, hence the slope is smooth. Why is energy lost in pushing the trolley up the incline?

2. Relevant equations
Ok, well obviously 44% of the energy is wasted, but I'm truly stuck as to why it is if there is no resistance force acting? Would it be the component of the weight which opposes the motion? Or that too much force is applied to move it? Any advice here would be much appreciated, I just simply don't know mathematically how to prove this loss and why? Thanks

2. Jun 2, 2013

PhanthomJay

Potential Energy is just one type of energy. Do you know of any others?