9.6 Forces and Torques in Muscles and Joints
Short muscle lever arms that demand huge internal forces, the back strain of poor posture, and the speed won by attaching close to a joint.
College Physics 2e, 9.6 Forces and Torques in Muscles and Joints
3 exercises
9.6 Exercise 1
When you use your hand to raise a 20 lb dumbbell in a curling motion, the force on your bicep muscle is not equal to 20 lb.
- Compare the size of the force placed on your bicep muscle to the force of the 20 lb dumbbell lifted by your hand. Using the concept of torque, which force is greater and explain why the two forces are not identical.
- Does the force placed on your bicep muscle change as you cu…
9.6 Exercise 9
Verify that the force in the elbow joint in the example is 407 N, as stated in the text.
Unreasonable Results
Suppose two children are using a uniform seesaw that is 3.00 m long and has its center of mass over the pivot. The first child has a mass of 30.0 kg and sits 1.40 m from the pivot. (a) Calculate where the second 18.0 kg child must sit to balance the seesaw. (b) What is unreasonable about the result? (c) Which premise is unreasonable, or which premises are inconsistent?
Adapted from College Physics © 2022 Rice University. Licensed under CC BY 4.0. Sources: College Physics 2e, College Physics for AP® Courses 2e. Imported at revision f98d7a7.