An object with a mass of #7 kg# is on a ramp at an incline of #pi/12 #. If the object is being pushed up the ramp with a force of # 2 N#, what is the minimum coefficient of static friction needed for the object to remain put?

1 Answer
Dec 28, 2015

The minimum coefficient of static friction is #0.237#

Explanation:

You have to visualize the force's diagram of the object.
Assuming the sistem with #x# on the surface of ramp and #y# on the normal of surface.
There is the orizontal component that is #F(x)=|2N-(mgsin15°)|=15.7N#
If the object remains "put": Friction Force=F(x)
#F(f)=CF(y)=C(mgcos15°)=15.7N#
and #C=15.7/66.33=0.237#.