Question

What is the coefficient of static friction between a load of mass 0.75kg and a horizontal surface if the limiting frictional force is 5N? (assume g= 10m/s)

Answer 1

The friction force

$$F=\mu N=\mu mg$$

So, the coefficient of static friction

$$\mu=\frac{F}{mg}=\frac{5\:\rm{N}}{0.75\:\rm{kg}\times 10\:\rm{N/kg}}=0.67$$