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: ->->->->->->->->->->->-> : Minimum tension=0
Maximum tension=3N.
Average tension=0+3/2=1.5N
• How much work is required to stretch the rubber band from 8 cm to 10 cm?
answer/question/discussion: ->->->->->->->->->->->-> : 3*0.02=.06Nm=0.06J
this should be based on average tension
• During the stretching process is the tension force in the direction of motion or opposite to the direction of motion?
answer/question/discussion: ->->->->->->->->->->->-> : Opposite to the direction of motion.
• Does the tension force therefore do positive or negative work?
answer/question/discussion: ->->->->->->->->->->->-> : Negative work
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: ->->->->->->->->->->->-> : the work done when the rubber band was stretched = energy released when the rubber band was released.=.06J in the negative direction this time.
• 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: ->->->->->->->->->->->-> :-.06J
• At this point how fast will the domino be moving?
answer/question/discussion: ->->->->->->->->->->->-> :1/2mv^2=.06
V^2=.06*2/.02=600
V=24.49cm/sec^2
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15mins
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Good, but see the link to reconcile a couple of errors. You'll understand:
&#Please compare your solutions with the expanded discussion at the link
Solution
Self-critique your solutions, if this is necessary, according to the usual criteria. Insert any revisions, questions, etc. into a copy of this posted document. Mark any insertions with &&&& so they can be easily identified. &#