Question

A 79 kg person sits on a 3.7 kg chair. Each leg of the chair makes contact with the floor in a circle that is 1.3 cm in diameter. Determine the pressure exerted on the floor by each leg of the chair, assuming all weight is evenly distributed.

Answer 1

I'll assume that the chair has four legs.

Since the chair weights 3.7 kg by itself, it will weigh (79+3.7)=82.7 kg with the person sitting on it. And each of the chair's legs will take about (82.7/4)=20.675 kg.

Each leg touches the floor in a circle with 1.3cm diameter. The area of that circle is about (3.14*(1.3/2)^2)=1.327 cm^2.

Pressure is measured by force per area. So, the pressure from each leg is about 20.675kg / 1.327cm^2. That simplifies to 15.58 kg/cm^2.