After some
research, I found the ultimate strength of a bird bone is about 31 MPa. I
converted this to Pa using: 31 MPa *
(1,000,000 Pa/1 MPa). Therefore, the bone has an ultimate strength of
about 3.1*10

^{7}N/m^{2}. Note that this is less than a human bone’s ultimate strength, which is about 1.3*10^{8}N/m^{2}.
I calculated the
force needed to break the wishbone using F/A=ultimate strength. I assumed the
diameter of a wishbone was about 0.5 cm, so it’s radius was about 0.25 cm or
0.0025 m. I calculated the area using A=πr

^{2}. The area was 2.0*10^{-5}m^{2}.
I calculated F= (3.1*10

^{7}N/m^{2})(2.0*10^{-5}m^{2}). The force required to break the bone is 620 N.
I then asked whether a person
could make the bone break in their favor (so they would get the larger piece of
the bone). I used to equation torque = rFsinθ. I assumed the wishbone was an
isosceles triangle and the angle was 30°.

If a person held the bone
about 5 cm or 0.05 m away from the center, the torque = (0.05 m)(620 N)sin(30)
= 15.5 Nm. If a person holds the bone closer, for instance at 3 cm or 0.03 m,
then torque = (0.03 m)(620 N)sin(30) = 9.3 Nm. The person at a longer distance
will exert more force so they will probably break the bone. A person could make
the bone break in their favor by holding the bone closer to its center. Happy
Thanksgiving!

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