Question

A 30 kg mass is resting on a rough, horizontal surface. A horizontal force of 100 N is required just to start it moving. What is the approximate value for the coefficient of static friction?

Answer 1

$F_s=\mu_s N$

where $F_s$ =friction force

$N$ = normal force

$\mu_s$ = coefficient of static friction

which can be written as;

$\frac{F}{mg}=\mu$

where F= force

m= mass

g= gravity

$\mu=$ coefficient of friction

substituting the given values in the equation

$\frac{100}{30\times10}=\frac{1}{3}$

Coefficient of static friction = 1/3