Can we do without friction?

Rubbing your hands together to make them warm.

Pushing a box across the floor.

What is common?

Write with a pencil

Playing football.

cause

Objects

contacts

making

FRICTIONFRICTION

A contact force that occurs when two surfaces oppose each other.

FRICTION

Sliding Friction

Static Friction

Friction between two solid objects that are not moving relative to each other.

Friction that occurs when an object slides over a surface.

Fluid Friction

Rolling Friction

Friction that occurs when a round object such as a ball or tire rolls on a flat surface.

Friction between layers within a viscous fluid that are moving relative to each other.

In various situations, friction is very important and beneficial.

Walk and Run Hold your Cup

Drive your Bicycle Apply breaks

Hammer your nail

Skiing through on the mountains Swim through water

Climb and Enjoy

Grindstone-sharpen a chisel Construction of buildings

Play gamesPaint your walls

Friction helps But a problem too…

Makes movement difficultExcess friction can make it difficult to slide a box across the floor, ride a bicycle or walk through deep snow.

Lubrication and use of ball bearings reduces friction.

Wastes energyFuel or energy is being wasted because of the friction.

Cars, airplanes and ships are streamlined to reduce friction.

Heats partsThe friction of parts rubbing together creates heat.

Wears things outAny device that has moving parts can wear out rapidly due to friction.

What will

happen without

Friction???

Slip while you run

Skid your bike

No fancy walls

Drown

No trekking

No Machines

No Flour

Friction – also known as necessary evil

As

Life is impossible without it.

We can minimize it but can’t get rid of it