[Sticks]

OK

Suppose we have

• body of weight W N
• Maximum pressure endured Pmax Nmm^-2
• Area of each pin is a mm^2
• And X pins

The weight must be distributed evenly the X pins and given the surface area of each pin this will be an area X.a

The maximum pain threshold Pmax is defined as force / area

This gives us:


Pmax = w / (X.a)

Rearranging gives


X = W / (Pmax.a)


An examination of the units show they cancel out

Plugging in the numbers gives 162.5

Since we canot have 0.5 of a pin, we round up to give the answer of 163 pins

Pluging the nuimbers back

Pmax = 650 / (163 * 1) = 3.99

Just under tollerance

QED