A gym goer is seated on a leg extension machine with his right knee joint flexed at 45°, lifting a 20kg gym weight at his foot, as shown in Figure 3(b). His body mass is W=100kg, and his lower leg mass is 0.06W. His height is h=1.80m, and the CGs of his lower leg and the gym weight act 0.15h and 0.30h from the knee joint center along the long axis of the tibia respectively. His knee extensor muscle force acts at an inclination angle of 17° with the long axis of his tibia, and a distance of 0.075h from the knee joint center along the long axis of the tibia. In addition, his quadriceps tendon forms an angle of 10° with the horizontal. Mass = 20kg Fw Figure 3(b) @ What type of skeletal joint is the knee joint? (ii) Draw a free body diagram, and compute the knee extensor muscle force Fax, knee joint reaction force Fy and its inclination angle o with respect to the horizontal. (iii) Draw a free body diagram, and compute the compressive reaction force Fp that he will experience at the patellofemoral joint, and its angle ô between the line of action of the compressive reaction force at the joint and the horizontal.

A gym goer is seated on a leg extension machine with his right knee joint flexed at 45°, lifting a 20kg gym weight at his foot, as shown in Figure 3(b). His body mass is W=100kg, and his lower leg mass is 0.06W. His height is h=1.80m, and the CGs of his lower leg and the gym weight act 0.15h and 0.30h from the knee joint center along the long axis of the tibia respectively. His knee extensor muscle force acts at an inclination angle of 17° with the long axis of his tibia, and a distance of 0.075h from the knee joint center along the long axis of the tibia. In addition, his quadriceps tendon forms an angle of 10° with the horizontal. Mass = 20kg Fw Figure 3(b) @ What type of skeletal joint is the knee joint? (ii) Draw a free body diagram, and compute the knee extensor muscle force Fax, knee joint reaction force Fy and its inclination angle o with respect to the horizontal. (iii) Draw a free body diagram, and compute the compressive reaction force Fp that he will experience at the patellofemoral joint, and its angle ô between the line of action of the compressive reaction force at the joint and the horizontal.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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