This question is driving me nuts. I really need help with it, actually i just need help setting up my equations.(adsbygoogle = window.adsbygoogle || []).push({});

Mu = the weird friction sympol

A box of a mass m=22 kg is at rest on a ramp inclined at 45 degrees to the horizontal. The coefficient of friction between the box and the ramp are "Mu s" = 0.78 and "Mu k" = 0.65.

a)Determine the magnitude of the largest force that can be applied upward, parallel to the ramp, if the box is to remain at rest.

My equation are:

Fn=Fgy - Fapp

Fnet = 0

also

Fnet = Fgx - Ffs

After that i end up getting two equations for Fapp but when i solve for it i get a negative answer. I also tried flipping Fapp so Fn=Fapp - Fgy but that also won't work, i get the wrong answer.

So can anyone please help get my two equations, theres something wrong with mine.

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# Homework Help: Another ramp question

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