I'm having trouble with the following problem:(adsbygoogle = window.adsbygoogle || []).push({});

"There is a car ready to go down a hill. The height of the hill is 9.0 m, and the length of the slope is 11.0 m (hypotenuse). The frictional force opposing the car is 125 N, and the car must be going 12.5 m/s when it reaches the bottom. What is the initial speed required for the car to overcome friction and reach required speed at the bottom of the hill?"

I set up the following equation: KE_i + PE_i + (frictional force)(cos 180)(11.0 m) = KE_f

I don't know if I have the right setup because whenever I try to solve it, I run into trouble because there is no mass provided and I get an answer to be around 50 (it should be a little less than 3 m/s).

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# Non-conservative forces

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