Question

A 1200Kg car travels at a constant speed of 26m/s for 5s up a 130m long hill. The total height of the hill is 27m & the friction force acting on the car is 2520N.
What power was used by the car in traveling up the hill?

I know that Fnet=o bc velocity is constant, therefore Fapp=2520N

I used (Fapp * d)/t so (2520 * 130)/5 to get 6.55 * 10^4

I got it incorrect... Am I supposed to do something with the height distance as well?

Thanks a bunch! :D

Answer 1

work against friction is
... 2520 N * 130 m

change in gravitational potential is
... m g h = 1200 kg * g * 27 m

the sum is the total energy

energy divided by time (5 s) is the power