Question

An object with a mass of `2 kg` is lying still on a surface and is compressing a horizontal spring by `80 c m`. If the spring's constant is `9 (kg)/s^2`, what is the minimum value of the surface's coefficient of static friction?

Answer 1

`mu = 3.6/g`

Explanation:

The force due to the static friction is `mu xx m g` and the force exerted by the spring is `K xx Delta x` The equilibrium is mantained as log as

`mu xx m g ge K xx Delta x`

then the minimum value for `mu` is

`mu = ( K xx Delta x)/(mg) = (9 xx 0.80)/(2 xx g) = 3.6/g`