The car with a mass of 800 kg ends up 2.5 m higher.
That means the energy required to haul it up the incline (50m horizontal with a slope 1 in 20 means 2.5 m vertical) is

800 kg * 9.81 m/s^2 * 2.5 m = 19620 J

The friction of 500 N is however expended over the distance crossed, 50 m.
500 N * 50 m = 25000 J

remember that F= m a; therefore
9.81 N = 1 kg * 9.81 m/s^2

Combine those two energy expenditure, and the total is 44620 J.

Oh, and perhaps you'd have better success if your did not flaunt your religion like you do, and concentrated on the only real truth: science.
God does not exist.

View the original article here