An object with a mass of 7kg is on a ramp at an incline of π12. If the object is being pushed up the ramp with a force of 6N, what is the minimum coefficient of static friction needed for the object to remain put?

1 Answer
Feb 2, 2016

μ=(6mgcos(π12)tan(π12))

Explanation:

From FBD:
Fi=Ff+F=μFN+mgsinα
Fi=μmgcosα+mgsinα
6=μmgcos(π12)+mgsin(π12)
Solve for μ
μ=6mgsin(π12)mgcos(π12)
μ=(6mgcos(π12)tan(π12))
Now pull out your calculator and voila!

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