AP Physics Submitting
Schedules Course Info Ch. Reviews Guides Problems Labs Videos AP Info AP Physics
Announcements Contact Shortcuts WebAssign Canvas Equations Lab FAQ Software IWP

The Concept of Pressure: Increasing Force with Area

player is loading....
Here we have a demonstration of pressure. What I have is a card board sheet with 576 pins arranged in a three inch by three inch square if I were to take one finger and apply just a small amount of force to anyone of these pins it wouldn't take much force to break my skin, but if I were able to use a larger area and apply could apply a larger amount of force while still having the same pressure as before and therefore I would not break my skin. So we'll demonstrate this by placing this on a bathroom scale and I'm going to press my hand down and don't try this at home but it really doesn't hurt at all and I'm applying twenty pounds of force to this bathroom scale and I'm still able to keep my hand in one piece. On a similar note we have this set of razor blades 100 razor blades and just as in the last demonstration if I were to apply force on anyone of these razor blades with my finger it wouldn't take much to slice my skin but with 100 of them together we have a larger area on which to apply a larger amount of force, still maintaining the same amount of pressure. So I'm going to demonstrate that by taking my fingers and squeezing really hard, so hard that you can see my fingers turning white and notice that they are still in one piece, so this shows that it works. Here we have a variation of the bed of nails What we have is a set of nails one inch apart from each other and if I were to a small amount of force as with the pins we saw earlier I'd certainly break my skin but Wisun in going to show us how to apply a large, much larger force, over a larger area.


© North Carolina School of Science and Mathematics, All Rights Reserved. These materials may not be reproduced without permission of NCSSM.