Learn more physics!
How can i explane to a group of 16 year olds how a bed of nails works?
- Sam (age 18)
Physics Org, Duluth
A bed of nails works in terms of the area that the force on the nails
is acting over. This has to do with the pressure that each nail is
exerting on a body. If there is one nail is on the bed, then all of the
force of the body is on the head of the nail. Since this a very small
amount of surface area that the force is being applied to, the pressure
is very large since P=F/A. This would cause a puncture is most
materials, including human skin. If this area is significantly
increased by adding a large amount of nails to the bed, then the
pressure would be diminished by a large amount. This causes the
pressure of each nail to not reach the necessay pressure to break
through materials. This would then allow someone to be able to sit on
nails and bring wonder to onlookers.
(republished on 07/18/06)
Follow-up on this answer.