Question

A wooden block of mass 1.9kg rests on a rough horizontal surface. If the limiting frictional force is 12N, calculate the coefficient of friction, take g =10m/s².

Answer 1

Applying the Newton’s Second Law of Motion, we get:

$$\sum F_x=ma_x=0,$$ $$F_{appl}-F_{fr}=0,$$ $$F_{appl}=F_{fr}=\mu N = \mu mg,$$ $$\mu=\dfrac{F_{fr}}{mg}=\dfrac{12\ N}{1.9\ kg\cdot 10\ \dfrac{m}{s^2}}=0.63$$

Answer:

$\mu=0.63$