(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I am doing a lab experiment and the objective is to find the efficiency of an elastic band.

Distance to ceiling=2.9m

Mass of elastic band= 1.85g

Force 2.6N (found using Newton meter)

Extension: 6.4cm

2. Relevant equations

Well I am not looking for a solution, I just need the way to setup the formulas in order to find efficiency.

F1=-kx (Hooke's Law)

F2=ma

3. The attempt at a solution

I think that I should compare the force stored in the elastic band as mechanical energy to the force required to make the rubber band hit the ceiling.

so I'd do this:

-kx=ma

Problem is that I don't know if acceleration should be taken to be gravity. Once I find acceleration, I should be able to find the initial velocity. Then, couldn't I use the work-energy theorem to compare the theoretical initial velocity to the actual velocity? Meaning, I compare the initial velocity I get when I use mgh=1/2mv^2 to the velocity I get when using acceleration.

Sorry maybe what I said above is completely wrong. Please help, I was missing from class when the teacher went over it.

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# Homework Help: Efficiency of an elastic band. Hooke's Law

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