# Sitting on a horizontal track is a mass of 10kg. One end of the track is raised untill the mass just begins to slip. If the coeffieient of static friction is .4 what is the minimum angle at which the mass begins to slip?

The component of force down the slope:

mgSinTheta

THe component of force (friction) up the slope

mg*mu*CosTheta

Set these equal, and solve for Theta.

Check my thinking.

mgSinTheta = mg*mu*CosTheta
(10)(-9.8)sin theta = (10)(-9.8) * (.4) * cos theta

then I got -98 sin theta = -39.2 cos theta

I don't understand how to solve for theta once I got this far.

Sitting on a horizontal track is a mass of 10kg. One end of the track is raised untill the mass just begins to slip. If the coeffieient of static friction is .4 what is the minimum angle at which the mass begins to slip?

mgSinTheta = mg*mu*CosTheta
(10)(-9.8)sin theta = (10)(-9.8) * (.4) * cos theta

then I got -98 sin theta = -39.2 cos theta

I don't understand how to solve for theta once I got this far.I also wasn't sure what "mu" in the above equation ment.

mu is the coefficient of friction

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