- #1

MrMechanic

- 46

- 0

## Homework Statement

Calculate the force P that is required to hold the 120lb roller at rest on the rough incline. (see attachments for Free body diagram)

## Homework Equations

Summation of Forces X = 0

Summation of Forces Y = 0

Summation of Moment along A = 0

Moment = Fd

## The Attempt at a Solution

well here's what i did...

Summation of moment along A = 0 [clockwise = positive]

-4(Psin15) + 4Pcos15 - 4(120sin15) = 0

P = 4(120sin15) / 4cos15 -4sin15

P = 43.923 lb

Which is wrong.. I've found out that the correct answer is 53.6lb

Can someone explain to me? on where did I go wrong.