Physics
posted by Phil .
A 13 cm long animal tendon was found to stretch 3.8 mm by a force of 13 N. The tendon was approximately round with an average diameter of 9.0 mm. Calculate the elastic modulus of this tendon.

URGENT

*First, calculate the area:
Area = (pi)r^2 = (π)4.5^2 = 63.6173 mm^2 = 0.0000636173 m^2
*Now, use this equation to find E, the elastic modulus:
E = (F/A) ÷ (ΔL/L0)
*Convert all length measurements to m and then plug and chug:
E = (13/0.0000636173) ÷ (0.0038/0.13) = 6 990 816.05 = 7.0 x 10^6
*Elastic modulus is measured in N per m^2, so the final answer is 7.0 x 10^6 N/m^2 
Further notes:
*Found r by taking diameter and dividing by two
*F = force = 13 N, listed in the problem
*A = area, which was found above (to convert from mm to m, multiply the mm figure by 10^3; to convert from mm^2 to m^2, multiply the mm^2 figure by 10^6, or twice the exponent of the conversion from mm to m)
*ΔL = 3.8 mm, listed in the problem
*L0 (a.k.a. "L initial") = 13 cm, listed in the problem 
Oh, and the equation for Young's modulus (the elastic modulus), E = (F/A) ÷ (ΔL/L0), is actually stress divided by strain:
Stress = F/A
Strain = ΔL/L0
Respond to this Question
Similar Questions

College Physics
As part of an exercise program, a 75 kg person does toe raises in which he raises his entire body weight on the ball of one foot. The Achilles tendon pulls straight upward on the heel bone of his foot. This tendon is 25 cm long and … 
Physics
The Achilles tendon, which connects the calf muscles to the heel, is the thickest and strongest tendon in the body. In extreme activities, such as sprinting, it can be subjected to forces as high as 13.0 times a person's weight. According … 
Physics
The Achilles tendon, which connects the calf muscles to the heel, is the thickest and strongest tendon in the body. In extreme activities, such as sprinting, it can be subjected to forces as high as 13.0 times a person's weight. According … 
physics
A 13 cm long animal tendon was found to stretch 3.8 mm by a force of 13.8 N. The tendon was approximately round with an average diameter of 7.0 mm. Calculate the elastic modulus of this tendon. 
physics
The figure is taken from a paper (Am J Sports Med 2004 32: 477) on injuries to the anterior cruciate ligament due to forces applied by the patella tendon. Take a particular case where the attachment force on the tibia is 5610N when … 
physics
When you stand on your tiptoes, your feet pivot about your ankle. As shown in the figure, the forces on your foot are an upward force on your toes from the floor, a downward force on your ankle from the lower leg bone, and an upward … 
physics
A 15cmlong tendon was found to stretch 3.7 mm by a force of 13.4 N. The tendon was approximately round with an average diameter of 8.5 mm. Calculate Young’s modulus of this tendon. 
Physics
The Achilles tendon, which connects the calf muscles to the heel, is the thickest and strongest tendon in the body. In extreme activities, such as sprinting, it can be subjected to forces as high as 13 times a person’s weight. According … 
Mechanics
A tendon is stretched slightly under the force T of 1000 N. How much will the tendon stretch under this load, in mm to one decimal place, if the diameter is 4 mm, the length is 30 mm, and the Young's Modulus is 1.5 GPa? 
Physics
Human feet and legs store elastic energy when walking or running. They are not nearly as efficient at doing so as kangaroo legs, but the effect is significant nonetheless. If not for the storage of elastic energy, a 70.0kg man running …