Tension in elastic cord at low point

AI Thread Summary
The discussion revolves around determining the tension in an elastic band when a metal cylinder reaches its low point after being suspended and given an initial downward motion. It is established that the tension at this point exceeds the weight of the cylinder, but the exact amount is unclear. The participant considers using kinematic equations and a motion sensor to measure acceleration, recognizing that tension varies with the cylinder's position. They are advised that by measuring the acceleration at the lowest point, they can apply the net force equation (Fnet = ma) to calculate the tension, which is the sum of the weight and the net force acting on the cylinder. Understanding the forces at play is crucial for solving the problem effectively.
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Problem:

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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Think about the forces acting on the cylinder at the lowest point.
 
I have. Weight and tension, with the tension being greater than the weight. I just don't see how that helps me determine the tension. I don't know how much greater the tension is, unless I'm missing something.
 
If you manage to measure the acceleration at the lowest point, then you can use
Fnet = ma to find the tension because the net force is given in terms of Tension and Weight as you correctly said.
 
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