Question

Why do lorries carry heavy loads have more tyres with spread tyres?

Answer 1

Lories carry heavy loads have more tyres with spread tyres because the carrying heavy loads use more tyres to reduce the pressure on its tyres. As the surface area increases the load is spread over a larger area and hence reducing the pressure. This reduction in pressure allows the lories to move batter and also protects the tyres from excessive wear and tear.

$\text{Pressure}=\frac{\text{Force}}{\text{Area}}$