11. Sara is standing on the ground with the right hip flexed 90° and the right knee flexed 55°, with the right ankle plantar flexed 90° such that it is in a straight line with the shank. If she wants to extend her knee with an angular acceleration of 200%/s², find the force she will need to exert with the quadriceps muscle group to do so. Assume that the quadriceps muscles and the weight of the leg are the only forces to be accounted for in this scenario. I Mass of shank and foot= 4.15kg Length of shank and foot= 0.55m Knee is flexed 55° + distance between line of pull of the quadriceps and knee joint center = 5.3cm Shank/Foot COM is in center of combined segments 2 Shank/Foot Moment of Inertia (1)= 0.217 kg*m

11. Sara is standing on the ground with the right hip flexed 90° and the right knee flexed 55°, with the right ankle plantar flexed 90° such that it is in a straight line with the shank. If she wants to extend her knee with an angular acceleration of 200%/s², find the force she will need to exert with the quadriceps muscle group to do so. Assume that the quadriceps muscles and the weight of the leg are the only forces to be accounted for in this scenario. I Mass of shank and foot= 4.15kg Length of shank and foot= 0.55m Knee is flexed 55° + distance between line of pull of the quadriceps and knee joint center = 5.3cm Shank/Foot COM is in center of combined segments 2 Shank/Foot Moment of Inertia (1)= 0.217 kg*m

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

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Concept explainers

Torque

Torque is the rotational equivalent of linear force in physics and mechanics. Based on the course of study, it is also known as the moment of force, rotational force, or turning effect.

Question

11. Sara is standing on the ground with the right hip flexed 90° and the right knee flexed 55°, with the right ankle
plantar flexed 90° such that it is in a straight line with the shank. If she wants to extend her knee with an angular
acceleration of 200%/s², find the force she will need to exert with the quadriceps muscle group to do so. Assume
that the quadriceps muscles and the weight of the leg are the only forces to be accounted for in this scenario.
Mass of shank and foot= 4.15kg
Length of shank and foot= 0.55m
Knee is flexed 55°
t
distance between line of pull of the quadriceps and knee joint center = 5.3cm
Shank/Foot COM is in center of combined segments
2
Shank/Foot Moment of Inertia (1)= 0.217 kg*m

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