Question

Explain with four examples that sometimes, force of friction is desirable.

Answer 1

I. Stopping of vehicles – If there were no friction then we cannot stop our vehicles and the vehicles continue to keep on moving and never stop. But there is friction which helps us to stop our vehicles because it opposes motion always.

II. Writing – When we write on paper or blackboard then the pencil lead gets dragged on the paper due to friction and gets deposited on the sight where we move it. If there were no friction then there would be no writing on paper with pencil.

III. Walking on ground – When we walk on the ground it is due to friction which gives us forward reaction force due to which we are able to walk and if there were no friction, then we would not able to walk.

IV. Picking of objects – When we pick objects this is only due to force of friction because gravity is always acting on objects and if we pick an object it’s net force should be zero in order for it to not move.