College Physics (10th Edition)
10th Edition
ISBN: 9780321902788
Author: Hugh D. Young, Philip W. Adams, Raymond Joseph Chastain
Publisher: PEARSON
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Chapter 10, Problem 60GP
The forces on the foot. A 750 N athlete standing on one foot on a very smooth gym floor lifts his body by pivoting his foot upward through a 30.0° angle, balancing all of his weight on the ball of the foot. The forces on the foot bones from the rest of his body are due to the Achilles tendon and the ankle joint. (See Figure 10.74.) The Achilles tendon acts perpendicular to a line through the heel and toes; it is this line that has rotated upward through 30.0°. Assume that the weight of the foot is negligible compared with that of the rest of the body, and begin by making a free-body diagram of the foot. (a) What are the magnitude and direction of the force that the floor exerts on the athlete's foot? (b) What is the tension in the Achilles tendon? (c) Find the horizontal and vertical components of the force that the ankle joint exerts on the foot. Then use these components to find the magnitude of this force.
Figure 10.74
Problem 60.
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A 50 N hand and forearm are held at a 35° angle to the vertically oriented humerus. The CG of the forearm and hand is located at a distance of 12.5 cm from the joint center at the elbow, and the elbow flexor muscles attach at an average distance of 2.5 cm from the joint center. (Assume that the muscles attach at an angle of 35° to the forearm bones.) How much force must be exerted by the forearm flexors to maintain this position?
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please solve thank you
A 50 N hand and forearm are held at a 35° angle to the vertically oriented humerus. The CG of the forearm and hand is located at a distance of 12.5 cm from the joint center at the elbow, and the elbow flexor muscles attach at an average distance of 2.5 cm from the joint center. (Assume that the muscles attach at an angle of 35° to the forearm bones.)
How much force must the forearm flexors exert if a 50 N weight is held in the hand at a distance along the arm of 25 cm?
Chapter 10 Solutions
College Physics (10th Edition)
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