- #1

- 26

- 0

## Homework Statement

Ignore B & C for now

**The block in the figure reaches a velocity of 40 m/sec in 100 m, starting from rest. Compute the coefficient of kinetic friction between the block and the ground.**

W = 100N

F = 40 N

2. Homework Equations

W = 100N

F = 40 N

2. Homework Equations

∑Fy = 0 so Normal Force = Weight

∑Fx = Force - Inertia - Frictional Force - Weight = 0

## The Attempt at a Solution

0.5 (V^2 -Vo^2) = as

0.5 (40^2 - 0) = a(100m)

a = 8 m/s^2

So I got this equation:

40 N = 100 N ( cos90) + 100N (8m/s^2 / 9.806 ) + 100 N ( μ)

I ended up getting a negative coefficient of friction which is

-0.415827. Is there something wrong with my equation?