Question

If you push a crate across a factory floor at constant speed in a constant direction, what is the magnitude of the force of friction on the crate compared to your push

Answer 1

The magnitude of the force of friction equals the magnitude of my push

Step-by-step explanation:

Since the crate moves at a constant speed, there is no net acceleration and thus, my push is balanced by the frictional force on the crate. So, the magnitude of the force of friction equals the magnitude of my push.

Let F = push and f = frictional force and f' = net force

F - f = f' since the crate moves at constant speed, acceleration is zero and thus f' = ma = m (0) = 0

So, F - f = 0

Thus, F = f

So, the magnitude of the force of friction equals the magnitude of my push.