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physicsjunkie1
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Homework Statement
This was a mini-lab and the task was to fire a rubber band by stretching it a known distance, shooting it straight horizontally from a known height. Based on where the rubber band lands determine the elastic coefficient. Known data from experiment: mass=0.30g, height=0.412m, distance flung=1.362m, stretched length (Δx)=0.047m.
Homework Equations
d=vt
Ee=1/2k(Δx)^2
Eg=mgh
Ek=1/2m(v)^2
The Attempt at a Solution
We tried to find the time with the vertical component
d=Vit+1/2at^2, acceleration is 9.8m/s^2
we got t=0.28997s
Then we used the horizontal component to get the velocity
d=vt
v=4.697m/s (initial velocity)
then we found the final velocity using a=(Vf-Vi)/(t)
we got Vf=7.53m/s (right before the rubber band hits the ground)
Then we thought that Eg+Ee (lost)=Ek (gained)
We solved for k, but got 6.62, which is not the right value because it is too small. There must be a problem with our method. We think maybe it has something to do with the acceleration formula used to find the final velocity. We aren't sure what we did wrong but let us know if you have any corrections or any other methods to approach this question with.