FrmrKSEngr wrote:WIederling wrote:FrmrKSEngr wrote:At a gross level that is correct, but assuming that each nail head is the same surface area, the contact load/pressure for each nail in the 200 nails configuration twice the value of of the 400 nail configuration. So while the 400 nail configuration doesn't pierce the surface, the 200 nail configuration might.

As long as the nails stick in the board the pressure is the same.

You distribute the same nn kg over the 1sqm.

What potentially changes is the number of nails pressing in your soles.

But, channeling Laurence of Arabia: the trick is to not show that it hurts

I guess it depends on which side of the board the nails are on. I was assuming the nails were contacting the tarmac (200 or 400 small points of contact) with the board on top. Assuming that the surface area of 400 nail heads is 40% of the board, and 100kg is placed on the board then the contact pressure at each nail head is 100kg/sqm X 1/40% = 250 kg/sqm. Going down to 200 nails of the same size, the contact area would be reduced by another 50%, for a total 20% contact area relative to the flat board, so the contact pressure would be 500 kg/sqm at each nail head.

this is the original experiment from Zeke:

"If you have two 1 sq meter boards,

hammer 200 nails on one, and 400 nails in the other,

turn them upside down and stand on each one in turn."

200 or 400 nails into one square meter of plywood or particle board.

Turn upside down.

Then stand on it.

If the nails are evenly distributed your feet/soles will stand on about

twice as many nails on the 400 mails/sqm as on the 200nails/sqm

Your weight will invariable be distributed over 1sqm ( assuming the boards are ideally stiff.)