A man holds a 178 N ball in his hand, with the forearm horizontal (see the drawing). He can support the ball in this position because of the flexor muscle force M, which is applied perpendicular to the forearm. The forearm weighs 20.2 N and has a center of gravity as indicated.

(a) Find the magnitude of M.

(b) Find the magnitude and direction of the force applied by the upper arm bone to the forearm at the elbow joint.

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A man holds a 178 N ball in his hand, with the forearm horizontal (see the drawing). He can support the ball in this position because of ...

Solution Summary

Forces exerted at the elbow joint and the forearm muscle are found using equilibrium principles for a person who is holding a ball in his hands. I have provided step-by-step solution to this classic question in physics.

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*Please see attachment for equations and diagram

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