Postlab 7 ANSWERS!

Postlab 7 ANSWERS! - Note regarding the angle: If the angle...

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2. As part of a physical therapy program following a knee operation, a 5-kg object is attached to an ankle and leg lifts are done as sketched in the figure. Calculate the torque about the knee due to this weight for the four positions shown. from the knee to the weight is 40 cm the four positions are at 0, 30, 60, 90 degrees. For the second part, remember that torque is the force (mass times g for weights) times the distance along a line drawn perpendicular to the direction of the force and through the pivot.
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Unformatted text preview: Note regarding the angle: If the angle between the force vector and vector from axis to point where force is applied is , then the torque is F*r*sin. However, in this problem, the angle is given as 30 from the *horizontal*, but the force (weight) is *vertical*, so the angle is 90 - , and the torque becomes F*r*cos. http://answers.yahoo.com/question/index;_ylt=AuQ6QmYMi2EOSrbuUQvrI2cjzKIX;_ylv=3? qid=20071207004620AArN5lC...
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