Question

An object with a mass of `1 kg` is lying still on a surface and is compressing a horizontal spring by `1/3 m`. If the spring's constant is `6 (kg)/s^2`, what is the minimum value of the surface's coefficient of static friction?

Answer 1

The coefficient of static friction is `=0.2`

Explanation:

The mass is `m=1kg`

The compression of the spring is `x=1/3m`

The spring constant is `k=6kgs^-2`

The reaction of the spring is `R=kx=6*1/3=2N`

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

The normal reaction of the object is

`N=mg=1*9.8=9.8N`

The coefficient of static friction is

`mu_s=R/N=2/9.8=0.2`