how long would a piece of thread need to be to break under its own weight?

Question

how about a humain hair?

Answer 1

The tensile strength of hair is 190 MPa (Reference 1). Let's assume a nominal hair diameter of 80 microns (Reference 2, black hair). So the breaking force for this hair is

fBreaking=pi*r^2*TS = 0.955 N

Because the body has so much water, let's assume that hair has about the same density as water, 1 gm/cm^3. If we hung the hair vertically, a hair of length 19 .3km would have a weight of 0.955 N. This hair would then break under its own weight.

Answer 2

It depends on the tensile strength S and density D of the thread. Given g=9.8 m/s^2, the length would be L=S/gD. This formula is valid if L is much smaller than the earth's radius.

Google Space Elevator. Carbon Nanotubes can go all the way up to to space if they could be made long enough.

Answer 3

Its a good question cuz if the thread was dangled like all of it straight it would never break .
But if you rolled it up like in a tight ball with just a thread to hang with the weight of the ball would get to a point where the thread would break. but what size the ball would have to get to is anynbodies guess depends on the thread .
Nylon would last longer than cotton.

Answer 4

I don't know the tensile strength of human hair. If you knew that, along with the density of the hair, you could figure it out. Interesting question though

Answer 5

Surf the internet to find the tensile strength of hair. I'm sure it varies from person to person depending on what conditioner you use. Same with thread. I think spider silks are exceptionally strong.

Answer 6

long enoght to wrap around Oscar Mayer Wiener 48201387064601640.221 times



but of corse that answer is off the top of my head

Answer 7

wow