I had some very interesting results for my science fair project. I had to do the experiment 3 times before I got it working. The first time, my dad and I bought the wrong kind of foam pipe insulation. It was made of rubber and too flexible to form a loop that held its shape. It was also pre-sliced on one side with sticky tape inserted in the slit. The tape prevented the marbles from rolling. The second time, I did the experiment but I realized that I needed much closer intervals between height changes for the ramp. Instead of 2 inch intervals for most of the time, I needed something like 1/16 inch intervals. But the third time was successful.
It started out by just having 10 marbles looping the loop (10 is the maximum). That was 21 13/16 in. The second time was 1/16 of an inch shorter. Only 9 made it this time. The marble fell off the ramp before it got to the loop. The third time was 3/16 inches shorter than the previous time. I couldn't do the height changes by the exact same interval every time because the supports were books (see the second picture below). We changed the height every time by removing or adding a book under the stack. Since all of the books are different heights, it would be impossible to make the height increase or decrease a 1/16 of an inch every time. All of the marbles made it the third and fourth time (21 7/16 of an inch). But now, the results get a bit more interesting.
The fifth time, all of the marbles made it but they were starting to go slower. The height this time was 20 5/16 of an inch. The next time, only half of them made it. By this time, some of the marbles are getting to the highest point of the loop and then they just fall down and off the track. What I find interesting is that the track got lowered only a fourth of an inch, yet now it makes a big difference in the results.
The seventh time is extremely odd. Seven of the ten marbles made the loop. That's more than last time! How can more marbles make it when it's an eighth of an inch shorter? I don't know. Then the next time was half and half, at 20 14/16 of an inch (simplified to 20 7/8 of an inch).
The height is now 20 11/16 of an inch. Only 2 marbles have completed the loop. The number of marbles that have made the loop are getting smaller and smaller. The next time (20 10/16 of an inch or 20 5/8 of an inch) is very similar to the seventh time. More marbles made the loop than before. This doesn't normally happen. The number of marbles that made the loop should be getting SMALLER as the height of the ramp decreases, not larger. Overall, the numbers are much smaller, but the numbers shouldn't be popping back up.
The eleventh time, none of the marbles made it. The height is 20 6/16 of an inch (20 3/8 of an inch). Even though none of the marbles made it, one marble was so close. It was about an inch away from completing the track. But it didn't make it. The twelfth time, the height was 20 4/16 of an inch (20 1/4 of an inch). One lucky marble made it to the end. It didn't exactly make the loop. It jumped over to the other track as it was going into the loop. Originally, I was going to end it here. But since this one marble made it, I decided I was going to lower the ramp one more time. The final time, the height was 20 3/16 of an inch. The number of marbles that made it was Z-E-R-O. None even came close.
Now I have my pictures. The first picture is a picture of my graph, showing how many marbles made the loop. The next picture is of the supports under the ramp. The one after that is a picture of the marbles. Then there are many pictures of the track, loop, and me. Finally, there is a video of the first time we ran marbles down the track.
It started out by just having 10 marbles looping the loop (10 is the maximum). That was 21 13/16 in. The second time was 1/16 of an inch shorter. Only 9 made it this time. The marble fell off the ramp before it got to the loop. The third time was 3/16 inches shorter than the previous time. I couldn't do the height changes by the exact same interval every time because the supports were books (see the second picture below). We changed the height every time by removing or adding a book under the stack. Since all of the books are different heights, it would be impossible to make the height increase or decrease a 1/16 of an inch every time. All of the marbles made it the third and fourth time (21 7/16 of an inch). But now, the results get a bit more interesting.
The fifth time, all of the marbles made it but they were starting to go slower. The height this time was 20 5/16 of an inch. The next time, only half of them made it. By this time, some of the marbles are getting to the highest point of the loop and then they just fall down and off the track. What I find interesting is that the track got lowered only a fourth of an inch, yet now it makes a big difference in the results.
The seventh time is extremely odd. Seven of the ten marbles made the loop. That's more than last time! How can more marbles make it when it's an eighth of an inch shorter? I don't know. Then the next time was half and half, at 20 14/16 of an inch (simplified to 20 7/8 of an inch).
The height is now 20 11/16 of an inch. Only 2 marbles have completed the loop. The number of marbles that have made the loop are getting smaller and smaller. The next time (20 10/16 of an inch or 20 5/8 of an inch) is very similar to the seventh time. More marbles made the loop than before. This doesn't normally happen. The number of marbles that made the loop should be getting SMALLER as the height of the ramp decreases, not larger. Overall, the numbers are much smaller, but the numbers shouldn't be popping back up.
The eleventh time, none of the marbles made it. The height is 20 6/16 of an inch (20 3/8 of an inch). Even though none of the marbles made it, one marble was so close. It was about an inch away from completing the track. But it didn't make it. The twelfth time, the height was 20 4/16 of an inch (20 1/4 of an inch). One lucky marble made it to the end. It didn't exactly make the loop. It jumped over to the other track as it was going into the loop. Originally, I was going to end it here. But since this one marble made it, I decided I was going to lower the ramp one more time. The final time, the height was 20 3/16 of an inch. The number of marbles that made it was Z-E-R-O. None even came close.
Now I have my pictures. The first picture is a picture of my graph, showing how many marbles made the loop. The next picture is of the supports under the ramp. The one after that is a picture of the marbles. Then there are many pictures of the track, loop, and me. Finally, there is a video of the first time we ran marbles down the track.
This is the graph of how many marbles made the loop. I hate the way that the website split the numbers along the "X" axis in half. But there's nothing I can do about it. You can see in the graph that the number of marbles that complete the loop are going down overall. But you also can see the number springing back up sometimes.
Now you can see the supports I used for the experiment. Most of them are my music books. But some are other books. I also have a box and a block of wood. The second time, we used the ironing board and raised it or lowered it. But it made the intervals too spaced out.
These are the marbles I used for the experiment. They are actually some of the magnetic ball bearings that are part of my toy magnet set.
This is a picture of me with the marble track. You can see the loop and the hill. This is actually the time when I was using the ironing board for the support.
This is a picture of me sticking my head in the loop. I am holding a marble. The track starts on the left and goes down the hill. Then the marble loops the loop and goes to the right and goes in a box.
This is a picture of me sitting next to the loop.
This is a picture of 3 marbles on the track.
This is a zoomed out version of the previous picture. Now you can see more of the track and the loop. I actually had two other pictures of the same thing.
This is a picture that shows the marbles going up to the loop. This picture has been taken so that it looks like you're hovering directly over the track!
This is the machine that I used to measure the height of the ramp. When this picture was taken, the height was 22 9/16 inch. This was the second time that we designed the test.
This is a video of me commenting on one of the times I ran marbles down the ramp (all of them made it here). My dad is the one holding the camera.