Question

Why a truck or a motor bus has much wider tyres

Answer 1

a truck or a bus has as a much wider tyre, to not to sink into the road (mud). If a truck or a bus has a much wider tyre the pressure applied by the truck or a bus on the Road is reduced.

Answer 2

as we know that pressure is depend on the surface area of any object.the wider the surface, the lesser the pressure.so this is the reason that why trucks and buses have wider tyres.