course Phy 201
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: 1 N would most likely be the minimum tension exerted and it is stated that at 10 cm length it is at 3 N so that would have to be the max. Therefore, it makes the average tension about 2 N.
• How much work is required to stretch the rubber band from 8 cm to 10 cm?
answer/question/discussion: 2 * . 02 = .04 Joules
• During the stretching process is the tension force in the direction of motion or opposite to the direction of motion?
answer/question/discussion: opposite
• Does the tension force therefore do positive or negative work?
answer/question/discussion: negative
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:
• 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:
• At this point how fast will the domino be moving?
answer/question/discussion: F = m * a
2 = .02 k g * a
A = .02 m / .02 kg
A = 1 cm/s
&#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. &#