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Phy 201
Your 'cq_1_14.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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A rubber band begins exerting a tension force when its length is 8 cm. As it is stretched to a length of 10 cm its tension increases with length, more or less steadily, until at the 10 cm length the tension is 3 Newtons.
• Between the 8 cm and 10 cm length, what are the minimum and maximum tensions, and what do you think is the average tension?
answer/question/discussion: ->->->->->->->->->->->-> :
I would say the minimum at 8cm would be 1N and the max would be 3N at 10. The average tensions would be 2N.
Right idea, but tension doesn't go from 0 to 1 N instantaneously; min would be 0 and max would be 3 N.
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• How much work is required to stretch the rubber band from 8 cm to 10 cm?
answer/question/discussion: ->->->->->->->->->->->-> :
since dW is netF* ‘ds I would say the 2N is the netF and 2cm is the ‘ds so therefore the ‘dW would be 4J.
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• During the stretching process is the tension force in the direction of motion or opposite to the direction of motion?
answer/question/discussion: ->->->->->->->->->->->-> :
I would say the tension force is in the opposite direction of motion.
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• Does the tension force therefore do positive or negative work?
answer/question/discussion: ->->->->->->->->->->->-> :
The tension force would have a negative work.
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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.
• Again assuming that the tension force is conservative, how much work does the tension force do on the domino?
answer/question/discussion: ->->->->->->->->->->->-> :
It would do about 1N*8cm, so 8J.
tension ceases at the instant the rubber band reaches the 8 cm length; the tension force is not exerted through an 8 cm displacement
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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: ->->->->->->->->->->->-> :
The KE is the negative of the work done so it would be -8J.
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• At this point how fast will the domino be moving?
answer/question/discussion: ->->->->->->->->->->->-> :
The domino will be moving 1N= .02(a)
Or .02cm/s/s.
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15 minutes
&#See any notes I might have inserted into your document, and before looking at the link below see if you can modify your solutions. If there are no notes, this does not mean that your solution is completely correct.
Then please compare your old and new solutions with the expanded discussion at the link
Solution
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