Rubber Band Lab

This week we used a rubber band and a force probe to find how we can store energy to do work for us later. We experimented with two different trails to find force (Fs) in terms of distance stretched (X). For the first trial, we used a single loop and stretched the rubber band to various lengths, while recording the force needed with the electronic force probe. Next, we had a double loop on the rubber band and repeated the experiment.

Units used:
m = metersN = newtons (force)K = elastic constantFs = force needed to stretchX = distance stretchedUs = elastic potential energy

Single loop data:
1 cm = .285 N
2 cm = .728 N
3 cm = 1.434 N
4 cm = 1.85 N
5 cm = 2.797 N
Double loop data:
1 cm = 2.31 N
2 cm = 3.866 N
3 cm = 6.22 N
4 cm = 8.32 N
5 cm = 11.72 N

In our graph we used  y=mx+b. In our graph force was on the y-axis and distance was on the x-axis, so we knew that the y variable would become Fs (force stretched) and the x variable would become X (distance stretched). We then found the slope of the line, which was 60 n/m. This was also the elastic constant (K). Because b=0, we derived the equation Fs=KX.

Real World Connection: 

The greater the distance the bow and arrow is stretched, then the greater the force needed to stretch, and the greater the potential energy. If you use a lot of force to pull the object back, the farther the object will go.