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Consider the following scenario:

An elastic band is used to suspend a metal cylinder vertically. The cylinder is given an initial

downward motion so that it moves down, reaches a low point, and then moves back up again.

Your challenge task is to determine the tension in the band at the instant that the cylinder is at its low point. You may use a motion sensor.

Attempt at a solution:

I know that the tension is greater than the weight of the cylinder at the low point, but I'm not sure how to determine by how much. I thought about using kinematic equations to find the acceleration at the bottom and from that the force, but we've only learned how to deal with constant acceleration and I'm sure that the tension in the band varies with the position of the cylinder. The only thing I've thought of is to use the motion sensor to make an acceleration graph somehow and find the acceleration at the lowest x point. But that seems more numerical than what we usually do in this class, so I figure there's probably a mathematical way.

Keep in mind that this is only my first physics class. We've just finished projectile motion and moved on to forces, so we haven't gotten to any special rules for springs or anything.

I appreciate any nudges to get me on the right track, if there is another way to think about this.

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# Homework Help: Tension in elastic cord at low point

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