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## Homework Statement

A crate of weight Fg is pushed by a force P on a horizontal

floor. (a) If the coefficient of static friction is us and P

is directed at angle theta below the horizontal, show that the

minimum value of P that will move the crate is given by

P = ( us*Fg*sec(theta)) / (1 - us*tan(theta))

(b) Find the minimum value of P that can produce motion

when us " 0.400

## Homework Equations

## The Attempt at a Solution

All right, I managed to do (a) on my own, but I'm dead stuck on (b). I've only gotten as far as inputting us = 0.400 in, and all I know is that I need to find an angle such that I get a minimum for P. I'm unsure as to how to solve this problem without inputting a bunch of angles and using trial-and-error to get my answer. Can anyone help me?