Question

Explain the friction applied force graph thoroughly.

Answer 1

Here is the friction vs applied force graph

when an object is at rest, there is static force of friction between it and surface.

The maximum force of friction is given as

F_max = uN

where N = weight of object

now, when we apply a force, the static force will resist the object from moving. We have to put a lot of effort to overcome this maximum force of friction. For any applied force less than maximum force of friction, the static force will match up to prevent motion.

once, we reach the point where the applied force is just equal to maximum force of friction, a motion threshold will occur means object is just about to move.

As we continue, the object will finally move and static force will no longer be there.

Then kinetic friction will come into action.

Remember, it take less effort to keep an object in motion than to get it in motion from rest. This is because static friction is always more than kinetic friction.

That's why we see a dip in the graph after motion threshold.