Question

An object with a mass of `18 kg` is lying on a surface and is compressing a horizontal spring by `30 cm`. If the spring's constant is `1 (kg)/s^2`, what is the minimum value of the surface's coefficient of static friction?

Answer 1

The coefficient of static friction is `=0.0017`

Explanation:

The mass is `m=18kg`

The compression of the spring is `x=0.3m`

The spring constant is `k=1kgs^-2`

The reaction of the spring is `R=kx=1*0.3=0.3N`

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

The normal reaction of the object is

`N=mg=18*9.8=176.4N`

The coefficient of static friction is

`mu_s=R/N=0.3/176.4=0.0017`