How much pressure is exerted on the floor?

Question

An 80 kg person supports all weight on two crutches, each crutch is circular with a diameter of 1 inch. What is pressure exerted on the floor in psi?

Answer 1

I weigh 120 lbs., and come up with 2880 psi., but, my crutch tips have rings to prevent slipping so the total area of the crutch tip does not contact the floor.  But all of that does not matter as long as I have them ot get around.

Answer 2

Let W = mg; be the weight of the m = 80 kg person, and g = 9.81 m/sec^2 on Earth's surface.  Work this to get the weight in Newtons.

Then w = W/2 = mg/2 is the weight on each of two crutches sharing the load equally.

p = w/A = ? the pressure on each crutch.  The contact area for each tip is A = pi(D/2)^2; where D = 1 in.

You have the numbers, you can solve the problem, but, and this is a big BUT, you need to be consistent with the units.  Newtons, for example, is not consistent with inches.  So you will need to convert the weight w to pounds before plugging into p = w/A.