Question

tyres of the vehicles need to be changed regularly why?

Answer 1

Typres of the vehicles need to be replaced after some time peroid because the grip of tire became older and the frictional force became less with acts with ground when brakes are applied so there is chance of accident.

Answer 2

vehicles are made of rubber which with time gradually gets rubbed against surface and thus this result in smoothing of tyres which in turn to make surface of the tyre smooth and flat and thus such tyres don't assure good grip