## Rubber Band carsBrian Nguyen, Ryan Fitzmaurice

#### |Rubber Band car Material|

Our first car, the original, it was made of two CDs, one skewer, modified 5"x5" cardboard piece, and duct tapes.

What are rubber band cars? They are car that are powered by band and they roll on two CDs. These two CDs function as wheels of the car and are attached to a skewer which is the axle. We are allowed to attach these two components using only duct tape.

#### How we make a rubber band car? How they work?

How do they work? First, we cut a "1 1/2 by 2" square in the middle bottom of the cardboard piece. Then we have the skewer go through the corrigation in the cardboard and put it in between the gap that we cut in the cardboard. We would tape the disc to the skewer, so it wouldn't fall off, but not a lot since we'll still want it to rotate. Above the place where we cut the cardboard, we tape one side of the rubbeband so, it would stick to the car and still be able to create energy. How we power our car? Well we put one side of the band on top of the skewer. Next, we would spin the skewer to wind up the rubberband, but not too much and this could create potential energy. Later, we would release the skewer, so we record how far our original rubber car can go and after that, we try to find the problem and try to find a modification for it.

If we pull the rubber band, it is storing the potential energy, and once we release the potential energy, or rubber band, it turns into Kinectic energy
We added duct tape to our car because we think it could stabilize our wheel and cause less friction. It went 16 feet after that.
We added rubber band because it causes less friction than duct tape, duct tape was bumpier than rubber band. It went 26 feet after that.
We added a skewer in the back because we think that it would stabilize our car. We also made a field goal cardboard design, and the reason why is because it's lighter than the original cardboard and could make our car go a farther distance. It went 26 feet sfter these modifications.
We added another skewer in the back in order to distribute the weight over a larger area better. It went 50 feet after applying the skewer, and taking out the rubber band on the wheel.

#### (Personal record in Distance for Rubbber Band Car)

This rubber band car went the farthest with 50 feet.

#### [Velocity and Acceleration]

Velocity is a cars speed over a course of time. This speed can be in any direction. The velocity is calculated by finding an item's change in position and dividing that by the amount of time it took to change that much position. For our final car that we talk about below it reached a top velocity of two meters per second.

Acceleration is the car's increase of speed over a period of time. To find this we chose two points on the graph below then calculated the acceleration using the formula. When testing a moving object you always want to know it's acceleration to see how fast it gets to it's top speed and at what rate.

The formulas

#### HOW WE USED THE VIDEO PHYSICS APP TO ANALYZE THE VELOCITY AND ACCELERATION?

Well, we used it to try to find the most accurate graph on its speed and distance by first recording a video of the rubber band car running from start to end. As you can see under us, it's the formula that we used to get the answer we seek.

Why did it have to be that recording angle? We recorded it in that camera view because we want to be able to record and see the car going from start to the finish line, so we can later analyze it and make a graph, in order to calculate its velocity and acceleration. We also made a measurement scale, so we could see how much the car had to travel. The measurement we used was one meter.

How we find velocity? We find velocity by having change in position/x over change in time/t. For example, we did 2m over 9 second and we got .1 for every .45 seconds.

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