Today in class, we were introduced what our Barbie project was going to be about. We were each given a barbie, rubber bands, measuring tape, as well as a thin rope which was optional to use. With these provided, we had to tie a rubber band on the doll’s leg, and make a bungee rope for her to safely jump without hitting the ground, but getting as close to the floor as possible. On the last day of our project, we were assigned to do a competition of which group had the best calculation to prepare for the best bungee jump. Furthermore, my group members for this project includes me, Arianna and June.
Basically, we started out by measuring everything such as the height of the desk from the floor which was 75cm, the weight of the barbie, which was 94.46g, and height of the barbie, 31cm. After we did that, we measured how many times she would fit between the 75 cm, which was about two times, and a little bit more. We first tried out using 5 bands (not including the one that was tied on her foot) and that worked perfectly fine. To further our investigation, we tried to do one in 150cm. Because we doubled the height, we also increased the amount of rubber bands by doubles which is 10. After that, we noticed that there was some space to fit just one more band, so we used 11 bands in total (again, not including the one band we used to tie her foot). Because this worked well, we recognized that we could write an equation which was: The Number of Rubber Bands = 2H (height) + 1.
We tried our experiment, and observed several times to see if she would hit the floor, or if it was too close, since we didn’t want our barbie to die. Not only that, but our group came up with the idea of also including the force of gravity into our equation (9.8m/s₂), since Arianna believed that it also influenced the way it worked. Furthermore, the problems we confronted with was trying to find out the pattern. We still don’t have enough data to really make sure that our equation is realistic. My predictions about it is that it won’t be exactly precise, but would somehow be close to the actual answer. Meaning that it might not help us get the perfect amount of rubber bands needed, but it would be very close.
On the other hand, the plan for my next class is to try out doubling the height to 300cm with 23 rubber bands to really see if our equation works. However, I’m not so sure if this would work since our classroom might not be 300cm in height, or who will put the meter stick that high. Due to that, I believe that we should try to start again with a smaller height, and see how that works. Not only that, but we will also try to see how much cm the barbie would go down with 1 rubber band, so that it helps even more with our equation. I hope that by next class, we will be able to find an accurate pattern for our project soon!
(Our beautiful Barbie taking risks)