Question

A girl of weight 600N sits on a 3-leg chair which weighs 60N. Each chair leg presses the floor in a circle with a diameter of 5cm. Find the average pressure exerted on the floor by each chair leg.

Answer 1

Pressure = total force/total area

Total force = 660 Newton's

Total area:

Each leg contacts the floor with an area of πr^2=π(0.025m)^2=0.002m^2.

Total contact area for all 3 legs = 0.006 m^2.

Pressure = (660N) / (0.006 m^2)

= 110,000 N/m^2 = 110,000 Pascal's.