Question

Explain why a heavy truck is fitted with 6 to 8 tyres?

Answer 1

because if area increases volume decreases and so less pressure is exerted on the ground

Answer 2

Trucks carrying heavy loads use eight tires to reduce the pressure on its tyres. As the surface area increases the force/load is spread over a larger area and hence reducing the pressure. This reduction in pressure allows the truck to move better and also protects the tyres from excessive wear and tear.