Posted by **Anonymous** on Wednesday, April 16, 2008 at 8:26pm.

If you ask a friend to drive a small nail into a piece of wood placed on top of a pile of books on your head. Why doesn't this hurt you?

- Physics -
**Damon**, Wednesday, April 16, 2008 at 8:44pm
Well, I would want a pretty massive pile of books and a light nail.

Force times time = change in momentum.

The hammer delivers a big force for a very short time. That force on a very small nail may change its velocity quickly (big acceleration with big force because of small mass.) However the big force does not last long enough to change the speed of the pile of books much (big force, big mass, small acceleration.) Therefore the pile of books does not transmit much force on to your heard.

If you want a headache, use a sledgehammer, big 20 penny nail, and a copy of Time magazine.

## Answer This Question

## Related Questions

- Physics warming a nail - 2.) Pounding a nail into wood makes the nail warmer. ...
- physics - a pneumatic nail gun with muzzle speed of 37m/s fires a 5.0cm nail ...
- math (find height) - A piece of construction paper is .01mm thick. It is cut in ...
- 4th Grade Math - 300 exercise books are arranged into 3 piles. The first pile ...
- PrimaryMatheMatics 4A textbook - 3000 Exercise books are arranged into 3 piles....
- Math - 400 exercise books are arranged into 3 piles.The first has 5 more books ...
- 4th Grade Math Correction - PLEASE HELP.I am sorry. I posted the question wrong ...
- physics - a pile drive has a 413 kg block that is lifted 1.4m and then dropped ...
- Physics - My problem is as follows "A 3 kg brick is dropped from a height of 1.0...
- Physical science - Using a hammer to drive a nail, it is the reaction force ...

More Related Questions