What Is the Initial Speed of a Block Given Friction and Distance?

[schyuler2]

Homework Statement

Find the initial speed of a block which travels 10m along a horizontal surface if \mu= 0.40 between the block and the surface before stopping.

Homework Equations

\SigmaW = 1/2mv_B² - 1/2mv_A² + mgy_B - mgy_A

\SigmaW = W * dAB * cos (W, dAB)

f = \mu* N
N= mgsin\theta

The Attempt at a Solution

so far i have:
\SigmaW = 0
\SigmaW = W_N + W_W + W_f

and

\SigmaW = W_W * dAB * cos (270)
\SigmaW = W_W * 10m * 0


not sure if I'm doing this right or where to go from here

 

[qnney]

This problem requires an equation that you haven't included yet.

So we'll start with:
\SigmaF = ma_x
\SigmaF = Px + fx + Nx + Wx
ma_x = Px + fx+ Nx + Wx

\mu = -a / g
Try to solve it from here.