Question

A 4800 kg truck is parked on a 12 ∘ slope.how big is the friction force on the truck? the coefficient of static friction between the tires and the road is 0.90.

Answer 1

The amount of friction on truck required to stop is = mass*g*sin(12)
= 4800*9.8*sin(12)
= 9780.16 newton

The maximum friction= coefficient of friction* force between tyres and road

Since maximum friction is more than required force to park the truck. Only required amount of friction will act.