Car moving up Inclined Plane question

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Ronaldo95163
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My question and attempted solution are in the pics below...not sure if what I did was correct though :/

I was thinking that the work done would have been equal to PE+Change in KE + Energy Lost to friction...but not sure how to calculate the energy lost to friction as I'm not sure if it has to be calculated in a specific form eg heat
 
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  • Photo of a printed exam question 4 on energy and mechanics, with parts (a) to (c) about kinetic and potential energy, a falling body, and a car on an incline; handwritten notes appear in the margin.
    IMG_20140309_004331.jpg
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  • Handwritten physics working on lined paper: an inclined plane of length 400 m and height 40 m with a car, force F_E up the slope and friction F_R = 200 N, followed by work-energy and force calculations.
    IMG_20140309_004223.jpg
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Work performed by a force = magnitude of the force x distance moved in the precise direction of that force. The energy expended will probably mostly end up as heat, but that is not important here.