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: The tension force at 8cm is 0 N and at 10cm is 3 N so therefore those are the minimum and maximum tensions. The average is simply 1.5N.
• How much work is required to stretch the rubber band from 8 cm to 10 cm?
answer/question/discussion: w = F*’ds = 3 * .02 = .06 J
• During the stretching process is the tension force in the direction of motion or opposite to the direction of motion?
answer/question/discussion: the tension force is opposite the direction of motion because it is trying to pull the object, the rubber band, back to its equilibrium.
• Does the tension force therefore do positive or negative work?
answer/question/discussion: the tension force does negative work I guess, I never really tried to look at it like that before.
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: would be the same, .06 J
• 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: e = is the same .06 J
• At this point how fast will the domino be moving?
answer/question/discussion: that’s what I can’t figure out… I’m hoping to learn that during this lesson.
set 1/2 m v^2 equal to the kinetic energy and solve for v
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20 min.
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Good. Check out the link and let me know if you don't completely understand the last step. No need to revise if you understand it.
&#At least part of your solution does not agree with the solution and comments given at the link below. You should view the solution at that link and self-critique as indicated there.
Solution
This link also expands on these topics and alerts you to many of the common errors made by students in the first part of this course. &#