Question

What are some real life examples of pressure (in psi please), more so surface and ground pressure examples? What is a real life representation of 1 psi surface/ground pressure? Calculations/reasonings behind these?

Thank you!

Answer 1

Explanation for Pressure :

Consider a surface immersed in a fluid. The surface can be real, solid surface such as the wall of a duct or the surface of a body. It can also be a free surface which we simple imagine drawn somewhere in the middle of a fluid. Also, keep in mind that the molecules of the fluid are constantly in motion. Pressure is the normal force per unit area exerted on a surface due to the time rate of change of momentum of the gas molecules impacting on that surface. It is a point property.

If the surface becomes smaller, the pressure becomes larger. for example, karate chop is much more effective than an open handed slap. If one were to slap a board squarely with one's palm, the only likely result would be a severe stinging pain on the hand. But if instead one delivered a blow to the board, with the hand held perpendicular provided, of course, one were an expert in karate,- the board could be split in two in the first instance. the area of force exertion is larger and the net pressure to the board relatively small, whereas in the case of the karate chop, the surface area is much smaller- and hence, the pressure is much larger.

It is normally measured in following units. bar, N/m² , psi.

For example, most recommended tire pressure for sports car is 32 psi to 40 psi.

Ground pressure is the pressure exerted on the ground by the tires or tracks of a motorized vehicle, and is one measure of its potential mobility, especially over soft ground. The ground pressure of motorized vehicles is often compared to the ground pressure of a human foot, which can be 60 - 80 kpsi while walking or as much as 13 mpsi for a person in spike heels.