course Phy 201
Does the tension force therefore do positive or negative work?answer/question/discussion: because there appears to be a force acting upon the rubber band, the rubber band will have a negative force acting against the motion
The rubber band is released and as it contracts back to its 8 cm length it exerts its tension force on a domino of mass .02 kg, which is initially at rest.
Does the tension force therefore do positive or negative work? You haven't committed to an answer to this question, although you have addressed just about everything you need to know in order to answer it.
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Again assuming that the tension force is conservative, how much work does the tension force do on the domino?
answer/question/discussion: W = 3 N * .02 m = .06 J
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Assuming this is the only force acting on the domino, what will then be its kinetic energy when the rubber band reaches its 8 cm length?
answer/question/discussion: KE = .06 J; the kinetic energy will be equal to the net work done on the object
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At this point how fast will the domino be moving?
answer/question/discussion: KE = 1/2mv^2 = .06 kg * m/s^2 * m = 2m * v^2; sqrt(.06 kg * m/s^2 * m) / 2(.02 kg) = sqrt(v^2); 1.2 m/s = v
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20 minutes
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Very good. See my first note; you have essentially corrected that error on your subsequent answers.
My second note deals with the question of whether the work done by the tension force is positive or negative. You don't have to resubmit this entire document, but you should submit a clarification of your answer to that particular question.
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I feel that the tension force does negative work because it is going in the opposite direction of motion.
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Good. That is correct.