Types of Friction

There are basically four types of friction:

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

Static Friction

It acts on objects when they are resting on a surface. For example, if you are hiking in the woods, there is static friction between your shoes and the trail each time you put down your foot. Without this static friction, your feet would slip out from under you, making it difficult to walk. In fact, that’s exactly what happens if you try to walk on ice. That’s because ice is very slippery and offers very little friction.

Sliding Friction

It is the friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction. That’s why it’s easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. For example, There is sliding friction between the brake pads and bike rims each time you use your bike’s brakes. This friction slows the rolling wheels so you can stop.

Rolling Friction

It is the friction that acts on objects when they are rolling over a surface. It is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards. For example: The ball bearings in this wheel reduce friction between the inner and outer cylinders when they turn.

Fluid Friction

Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases. If you’ve ever tried to push your open hand through the water in a tub or pool, then you’ve experienced fluid friction. Another example could be a swimmer, cutting through the edges of water where the water provides fluid resistance to the swimmer.

Friction is a force between two surfaces that are sliding, or trying to slide, across each other. For example, when you try to push a book along the floor, friction makes this difficult. Friction always acts in the opposite direction to the movement of the object i.e. it opposes the motion of an object. Friction always slows a moving object down.

The amount of friction depends on the materials from which the two surfaces are made. The rougher the surface, the more friction is produced. Friction also produces heat. If you rub your hands together quickly, you will feel them get warmer.

Advantages of Friction

• Friction is responsible for many types of motion
• It helps us walk on the ground
• Brakes in a car make use of friction to stop the car
• Asteroids are burnt in the atmosphere before reaching Earth due to friction.
• It helps in the generation of heat when we rub our hands.

Disadvantages of Friction

• Friction produces unnecessary heat leading to the wastage of energy.
• The force of friction acts in the opposite direction of motion, so friction slows down the motion of moving objects.
• Forest fires are caused due to the friction between tree branches.
• A lot of money goes into preventing friction and the usual wear and tear caused by it by using techniques like greasing and oiling.