(Solved) Calculate work done by friction and by the the weight of a person on an inclined slide?

Calculate work odne by the person's weight,

WE = FE + PE; work energy is the friction energy plus the lifting energy. FE = W cos(theta) kS; where W is the person's weight W = mg, theta = 60 deg, k = .1, and S = 5 m. PE = Wh = mgh; where h = 2.5 m height. Thus the total work done by the weight (W) of the person is WE = mgkS cos(theta) + mgh = mg(kS cos(theta) + h). [Note...weight is the driving force for both the friction work and for the decrease in height as the person slides down the ramp.]

work done by the normal reaction force from the slide and

N = W cos(theta) = mg cos(theta) and Sn = 0, which is the distance pushed by the normal weight. Thus WE = NSn = mg cos(theta)*Sn = 0. So the normal force does no work as it does not move the person in the normal direction at all.

work done by friction.

FE = NkS = mg cos(theta) kS, as indicated earlier. [NB: The work is not done by the friction; friction does not move things. The work is done by the force of gravity (weight) to overcome friction and move the person along the ramp.]

The physics is this...the total work WE is the sum of the work done by gravity against the friction and done by gravity in lowering the height of the person. to ground level. It is not, as suggested by another answer, just the vertical work.

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Calculate work done by friction and by the the weight of a person on an inclined slide?

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