Question

A boy exerts a horizontal force of 123 N on a crate with a mass of 33.2 kg.

If the crate doesn't move, what's the magnitude of the static friction force (in N )?

Answer 1

The magnitude of the static friction force is 123 N, which is equal to the applied horizontal force because the crate is stationary.

Step-by-step explanation:

If a boy exerts a horizontal force of 123 N on a crate with a mass of 33.2 kg and the crate doesn't move, then the magnitude of the static friction force acting on the crate is also 123 N. In static equilibrium, the static friction exactly balances the applied horizontal force to prevent the crate from moving. Therefore, the static friction force must be equal to the applied force when the crate is stationary, assuming the applied force does not exceed the maximum static friction force possible between the two surfaces (which, in this case, we do not have enough information to calculate).