Satisfying application of physics

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leftyguitarjo
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Today, I completed a lab test in my physics test, and received the highest grade in the class. The goal was to simulate a bungee jump. We had to make the payload, an egg in my case, get as close to the floor as possible without touching. To do this, you get a rubber band, and would then calculate a length of non-elastic string to attach to it. Our goal was within 3cm. The catch? you only get one try. I first got a large rubber band, and suspended it from a fixed arm about 2m off the floor. I measured the displacement of the rubber band, and use a force gauge to measure the force. I used those numbers in F=-kx to find the spring constant. I then found the elastic potential energy with Pe=1/2kx^2. I then took the weight of the egg, in Newtons, and calculated the string length with P(elastic)=P(egg) and got .5m. My egg, dropped from the same point that the rubber band was attached to the support, was dropped, and promptly sprang back upon reaching 3cm almost exactly.:approve:Just to sum up my work:
F=kx
9=13.84(.65m)

P(elastic)= 1/2kx^2
2.96= 1/2(13.84).65^2

2.96=mgh

2.96=.6(9.8)h

h=.5m
 
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ZapperZ said:
Very, very good! That's the kind of physics "lab" that I like.

Zz.

thank you very much.

and BTW, I just met with my college course adviser for the first time today. I am "in", and I'm majoring in physics!
 
leftyguitarjo said:
thank you very much.

and BTW, I just met with my college course adviser for the first time today. I am "in", and I'm majoring in physics!

Great job!

I've had a few similar labs that just *worked* but most of these consist of overcomplicated setups that just manage to work, pure fluke.