Question

give two examples to show that friction is both our friend or foe

Answer 1

when you drive a bicycle , imagine the road is smooth as silk , there will be no friction, hence you will fall down.At this time friction helps you to drive without accident.

you know that when there is friction heat is also produced , if the heat produced is so much it leads to many problems like forest fires.

Answer 2

In certain industries friction makes wearing and tearing of the rubber tyres or substances used in the machines. It produces heat energy and thus most of the energy is lost. But we cannot totally avoid friction as without friction we cannot eide a bicycle or walk properly or apply brakes in cars.