Question

An object with a mass of `14 kg` is lying still on a surface and is compressing a horizontal spring by `70 c m`. If the spring's constant is `2 (kg)/s^2`, what is the minimum value of the surface's coefficient of static friction?

Answer 1

The coefficient of static friction is `=0.01`

Explanation:

The mass is `m=14kg`

The compression of the spring is `x=0.7m`

The spring constant is `k=2kgs^-2`

The reaction of the spring is `R=kx=2*0.7=1.4N`

The acceleration due to gravity is `g=9.8ms^-2`

The normal reaction of the object is

`N=mg=14*9.8=137.2N`

The coefficient of static friction is

`mu_s=R/N=1.4/137.2=0.01`