Know About Friction!

Friction

Friction is the force that opposes the motion of an object.

For instance, if you push your book across your desk, the book will move. The force of the push moves the book. As the book slides across the desk, it slows down and stops moving. The force that opposes the motion of an object is called friction.

Types of Friction

1. Static Friction
2. Sliding Friction
3. Rolling Friction
4. Fluid Friction

• Static Friction

A force that keeps an object at rest. It must be overcome to start moving the object. Once an object is in motion, it experiences kinetic friction. If a small amount of force is applied to an object, the static friction has an equal magnitude in the opposite direction.

Now let's look at the formula for static friction force. The static friction force (F(f, static)) is less than or equal to the product of the coefficient of static friction (µ(s)) and the normal force (F(N)).

• Sliding Friction

Sliding friction refers to the resistance created by any two objects when sliding against each other

A book moving across the desk is an example of sliding friction. As the book slides on the desk, the bottom of the book is touching the desk. The source of the friction is the contact between the surface of the book and the desk.

• Rolling Friction

Rolling friction occurs when a round object rolls around a surface.One can obviously conclude by now that the study of rolling friction is limited to wheels or rollers and the surface on which they move.

Examples of rolling friction in everyday life

1. A basketball rolled on the court will eventually come to a halt because of rolling friction.
2. A bike with a broad tire will burn more fuel because of the increased rolling friction.
3. A ball rolled on a field will go lesser distance than a ball rolled on a concrete floor because it will experience greater rolling friction on the former surface.

• Fluid Friction

Fluid friction is the force that resists the movement of a solid object through a fluid.

(Note-Fluid is anything which can flow or has fluidity Eg- Gases or Air)

Examples of Fluid Friction

1. If there is a wet surface between two thin glass plates, you will notice that plates get stucked and the bottom plate doesn’t fall when you hold only the top one.
2. When any object is dropped in a fluid, the extent of splash is depended on the fluid friction of that particular fluid.
3. You find lighter dust particles move fast on the surface of a flowing river. This is due to the high-velocity gradient at the top layer of water due to lower dynamic fluid friction at that layer