A simplified model of a human arm holding a weight is shown on the right. The length of the forearm is 40 cm and it has a mass of 1.7 kg. The bicep muscle is attached 4 cm in from the elbow joint and makes an angle of 73° with the forearm. The weight in the person's hand has a mass of 5 kg.

A simplified model of a human arm holding a weight is shown on the right. The length of the forearm is 40 cm and it has a mass of 1.7 kg. The bicep muscle is attached 4 cm in from the elbow joint and makes an angle of 73° with the forearm. The weight in the person's hand has a mass of 5 kg.

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter9: Statics And Torque

Section: Chapter Questions

Problem 9PE: A person carries a plank of wood 2.00 m long with one hand pushing down on it at one end with a...

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Question

Problem 5:
Fr
Fm
Bone
-Muscle
100
30 cm
W
4 cm
40 cm
A simplified model of a human arm holding a weight is shown on the right. The length of the forearm is 40 cm
and it has a mass of 1.7 kg. The bicep muscle is attached 4 cm in from the elbow joint and makes an angle of
73° with the forearm. The weight in the person's hand has a mass of 5 kg.
a) What is the magnitude of the force provided by the bicep muscle needed to keep their arm at rest?
b) What is the magnitude and direction of the force acting at the elbow (F;) in that same case?

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