# A 65.7 kg skateboarder is sliding down a 15 meter long incline. The incline is 7.50 meters tall. As he slides down he encounters 96.5 N of friction. How fast is the skateboarder moving at the bottom of the hill?

##### 1 Answer

Nov 23, 2015

I found

(by the way, check my maths!)

#### Explanation:

At the top of the incline he will have gravitational potential energy

Kinetic Energy:

and

Heat due to friction equal to the "work" done by friction:

So the Kinetic Energy "available" to move the skater at the bottom of the incline will be the initial potential energy minus the energy used to heat up the ramp:

or