You just answered your own question. Work = Force x Displacement (parallel to the force).tubworld said:I agree that it's to have sufficient enrgy to overcome resistance to continue the loop at its highest pt, but what has energy got to do with force? I only remember that force * displacement of force = energy.
The problem tells you the average frictional force is F. So all you need is the distance the block travels in getting up to the top. (Yes... it's half the circumference. It's that simple.)But in this case. the frictional force doesnt travel on a st line, making it hard to calculate the ans. I cant possibly take the diameter as the displacement right? Neither can I take the perimeter of half a circle as the displacement?