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College Physics
11th Edition
ISBN: 9781305952300
Author: Raymond A. Serway, Chris Vuille
Publisher: Cengage Learning
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If you hold your arm outstretched with palm upward, as shown, the force to keep your arm from falling comes from your deltoid muscle. The arm of a typical person has mass 4.0 kg and the distances and angles shown in the figure.
a. What force must the deltoid muscle provide to keep the arm in this position?
b. By what factor does this force exceed the weight of the arm?

Transcribed Image Text:15° Deltoid
17 cm
38 cm
FIGURE P8.49
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