T=s*g*(m_1+2*m_2)/d
F=-(m_1+m_2)*g+s*g*(m_1+2*m_2)/d
You are holding a ball of mass m2 in your hand. In this problem you will solve for the upward force T⃗ that the tendon of your biceps muscle exerts to keep the forearm horizontal and the downward force F⃗ that the upper arm exerts on the forearm at the elbow joint. Assume the outstretched arm has a mass of m1 , the center of mass of the outstretched arm is a distance s from the elbow, the tendon attaches to the bone a distance d from the elbow, and the ball is a distance 2s from the elbow. (Taking T⃗ to be upward and F⃗ to be downward, with no horizontal components, indicates that this is a simplified model. ) A schematic representation of this situation is shown below:
Hint: The forces can be modeled as shown in the following Free Body Diagram:
(a) What is the magnitude of the tension T≡∣∣T⃗ ∣∣ in the tendon? Express your answer in terms of s, m1, m2, d and g as needed.
T=
(b) What is the magnitude of the force that the upper arm exerts on the forearm at the elbow joint? Express your answer in terms of s, m1, m2, d and g as needed.
F=
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