Why a truck or a motor but has much wider tyres?

Why is the foundation of wall made wider?

A 20kg box rests on the flat floor of a truck. The coefficients of friction between box and floor are mu_(s) = 0.15 and mu_(k) =0.10. The truck stops at a stop sign and then starts to move with an acceleration of 2 m/s^(2) . If the box is 2.2 m from the rear of the truck when the truck starts, how much time elapses before the box falls of fthe rear of the truck? How far does the truck travel in this time.

Why is it recommended that tha air pressure in motorcar tyres be reduced for a motion of the motorcar over sand ?

Why a liquid rises more in a capillary with narrow bore than same with wider bore?

Why carts with rubber tyres are easier to ply, than those with iron tyres?