- #1

- 58

- 0

## Homework Statement

An incline makes an angle of 29.9° with the horizontal. A 8.87 kg block is given a push up this incline and released. It starts at the bottom with initial speed 6.43 m/s, travels up the incline, stops, and slides back to the bottom at final speed 4.49 m/s. Using energy considerations, find:

a) the energy used to overcome friction traveling up and down the incline.

b) the distance the block traveled up along the incline before coming momentarily to rest.

c) The coefficient of kinetic friction between the block and the incline.

## Homework Equations

Components (mgsinθ, mgcosθ)

W=Fs

P=Fv

KE=1/2*m(vf)^2 - 1/2*m(vo)^2

## The Attempt at a Solution

I attached my FBD.

To find the energy, I would use the KE equation.

KE= 1/2*8.87*0 - 1/2*8.87*(6.43)^2 = (-183.4) J

So it took -183.4 J to climb up the incline which includes friction?

I'm not sure, but I guess we could do this:

P=Fv

-183.4 = (F)(6.43)

F = (-28.5N)

To find the distance (part b), W=Fs

(-183.4)=(-28.5)s

s=6.44m

Part (c), I'm confused..

Ff = μk*N

Ff+mgsinθ-F=μk*mgcosθ