Variant i Interactive tutorial lecture
Students apply the concepts of force and torque to model the human arm as two rods connected by a hinge and string.
Topics Mechanics / Rotation: models, vectors, approximations, forces, geometry, Newton's second and third laws, torque, and vector addition & subtraction
Section I: Biceps contractions
In Questions A-D, students consider how the biceps muscle can cause the forearm to rotate toward the upper arm. Students then model the arm as two rods with a hinge (elbow) connected by a string (the tendon). In Questions E-F, students apply their model to the case of a person doing a biceps curl or similar exercise.
Then students use the rotational equivalent of Newton’s second law to determine how the heaviest weight a chimpanzee can support compares to that of a human.
Section II: Triceps contractions
In this section students use a similar model for thinking about the role of the triceps muscle, then use their model to make calculations.
Section III: Supplement
This section guides students through a model of the head and neck muscles of an American football player. Students do computations concerning the force the neck muscles provide to keep the head from rotating in different scenarios.
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There is a review of the definition of torque at the beginning of the tutorial, but it is best if students have already been introduced to torque and the idea of a moment arm.
Coming Soon! We hope to release the discussion section on each tutorial by the end of September 2024.