An object with a mass of 15kg is lying on a surface and is compressing a horizontal spring by 40cm. If the spring's constant is 4kgs2, what is the minimum value of the surface's coefficient of static friction?

1 Answer
Apr 16, 2016

Force F required to compress a spring by x unit is
F=kx,where k = force constant.
Here x=0.4m
k=4kgs2
hence Force exerted on the object of mass 1 kg is F=4kgs2×0.4m=1.6kgms2=1.6N
This force is balanced by the then static frictional force as it is self adjusting one,

So the minimum value of the coefficient of static frictions
μs=FN,where N is the normal reaction exerted on the body by the floor. Here N=mg=159.8N
So
μs=FN=1.69.8×15=0.011