Question

according to static,kinetic and rolling friction which one is greater and give reasons​

Answer 1

Rolling resistance is usually less thanstatic friction because the surface of contact is very very small in real life so the net normal force is also small and not enough like the static friction to prevent the body from sliding and keep it unmoved and static friction also increases with the increase of the external ...

Answer 2

Hi, my friend.

I'll take an example and show it to you.

1st case) Lets say you have a box of chocolates and you keep the box on the carpet.

In this case, the box is at rest. So there is only one force acting on it.

(Note: We don't consider weight force and Normal force since this is a question about friction. )

i.e. the static friction is acting now.

2nd case) Now you push the box i.e. apply some force from one side

So that the box begins to move.

In this case, the box is at motion

(Now also, we neglect Weight force and Normal force since the acceleration of the body is horizontal and the question is about friction)

Here too there is only one force acting i.e. Kinetic friction

(Since the body achieves some velocity and so it achieves some kinetic energy. )

3rd case) Let the box be at rest. You attach four wheels for the box. Now a slightest push can convert the box from rest to motion.

(Now also, we neglect Weight force and Normal force since the acceleration of the body is horizontal and the question is about friction)

Here too there is only one force acting i.e. Rolling friction.

The force required to change the body from rest to motion is known as limiting force.

Here limiting friction exists from the static friction.

Now, from this experiment we see that

It takes most force to start the motion of the body from rest.

Hence Static friction is the most compatively.

And it doesn't need too much force to continue it's motion also because Newton's first law says so.

Hence Kinetic friction is less than static friction.

There is no need to apply force when it is on wheels.

Hence Rolling friction is least.

Harith

Maths Aryabhatta

Physics Genius