Question

A body of mass 37 kg rests on a rough horizontal surface. The minimum horizontal force required to just start the motion is 68.5 N. In order to keep the body moving with constant velocity, a force of 43 N is needed. What is the value of coefficient of kinetic friction?

Answer 1

Given: F_L = 68.5 N, F_k = 43 N, m = 37 kg, g = 9.8 m/s²

To find: Coefficient of kinetic friction (μ_k)

Formula: μ_k = `("F"_"k")/"N" = ("F"_"k")/"mg"`

Calculation:

From formula,

∴ `mu_"k" = "F"_"k"/"N"`

= 43/(37 xx 9.8)`

= 0.1186

∴ The coefficient of kinetic friction is 0.1186.