- #1

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## Homework Statement

A 2 kg block rests on an inclined plane with an angle of 30. A force of 5 N is applied to the block in a direction down the incline plane until the block begins to move when the force reaches 7.3 N, what is the approximate coefficient of static friction between the block and the plane?

## Homework Equations

None

## The Attempt at a Solution

I made a FBD, labeled normal, weight (and its x and y components), the F

_{f}, and the F

_{applied}. I made a force table to lay out all the knowns:

F

_{n}Weight F

_{applied}F

_{f}

n

_{x}=0 W=mg F

_{AX}=-7.3N F

_{f}=μn

n

_{y}=+n W

_{x}=-10N F

_{AY}=0N F

_{fx}=μn

W

_{yy}=-17.3N F

_{fy}=0N

ΣF

_{x}=ma

_{x}ΣF

_{y}=ma

_{y}

0-10-7.3+μn = 2a

_{x}n-17.3 = 2(0)

-17.3 + μ

_{s}n = 2a

_{x}n = 17.3 N

In ΣF

_{x}, I have 2 unknowns. How to solve for μ

_{s}?