posted by Jailyn .
Why are some things"in" and some things"out" Think about a certain force.
IN:paper clip, nail, thumb tacks
Out: paper cup, shoe, carpet
Interesting. I never really thought about it. Nails and thumb tacks have a force holding things together. Same for a paper clip holding several sheets together. Paper cups and shoes hold something inside such as water or feet.
The same force applied to a sharp object makes much more pressure to penetrate. THe force spread out over a large area, as a shoe, will not penetrate. Now think on a woman's high heel shoe, the heel part: small area: does it penetrate soft floors?