What I did
As You can see above,I first drew the models of the card cars. I drew 2 main models, but used the second one since it was more unique and seemed like it could decrease the air friction. So, we started building afterwards. We could only use certain materials. They were;
-3 X 5 index cards (maximum of 3)
-2.5” long X 1/8” diameter steel axles (maximum of 2)
-Four plastic wheels, outside diameter of less than 40 mm
-Transparent tape (maximum of 6 inches total)
With these, we made a card car as you can see to the right. Afterwards, we designed the car with a sharpie. Then, as we were racing, we had to put a certain weight of clay to the car. So I thought, why not make it interesting than other people? and shaped the clay like a person. This way, it seemed as if a guy was riding a wagon. Anyways, the results were fantastic since we got first place. It went the furthest and it went the straightest. Well, we used science while building this card car. There were two kind that applied to this car; gravity and rolling friction.
-3 X 5 index cards (maximum of 3)
-2.5” long X 1/8” diameter steel axles (maximum of 2)
-Four plastic wheels, outside diameter of less than 40 mm
-Transparent tape (maximum of 6 inches total)
With these, we made a card car as you can see to the right. Afterwards, we designed the car with a sharpie. Then, as we were racing, we had to put a certain weight of clay to the car. So I thought, why not make it interesting than other people? and shaped the clay like a person. This way, it seemed as if a guy was riding a wagon. Anyways, the results were fantastic since we got first place. It went the furthest and it went the straightest. Well, we used science while building this card car. There were two kind that applied to this car; gravity and rolling friction.
What I Learned
From looking at the other card cars my friends made, I learned a lot. First of all, I learned that the card car needs to be sturdy since there were a lot that fell apart during the race. Also, the wheels need to be in good shape or it will roll away to the side. Another thing I learned was that the paper needs to be put in good shape or the card car will go slower. From these things I learned, I tried to put science in them. These will be explained in the concepts.
Concepts
Gravity
The card car already has some weight on because of the card and the glue. But since we had to add a certain weight of clay on this, more gravity pulled the car downwards. Also, the car started at the top of a slide so the gravity made the car roll down. Using this, we made the car sturdy so it wouldn't bread from the weight of the clay. This way, the card car could slide smoothly downwards.
Rolling friction
We tried to first make the bottom strong so we could put a bit of clay and get move fluently. The way to do this was to put 2 cards and glue them with the glue. Also, we wanted the car to go fast, so we tried to reduce the friction. The frictions that is caused in this car was rolling friction. As the wheels rolled, there was friction so the car slowly stopped. In order to stop this, we got a sand paper and tried to make the wheels as smooth as possible. This way, the car rolled more fluently and faster.
The card car already has some weight on because of the card and the glue. But since we had to add a certain weight of clay on this, more gravity pulled the car downwards. Also, the car started at the top of a slide so the gravity made the car roll down. Using this, we made the car sturdy so it wouldn't bread from the weight of the clay. This way, the card car could slide smoothly downwards.
Rolling friction
We tried to first make the bottom strong so we could put a bit of clay and get move fluently. The way to do this was to put 2 cards and glue them with the glue. Also, we wanted the car to go fast, so we tried to reduce the friction. The frictions that is caused in this car was rolling friction. As the wheels rolled, there was friction so the car slowly stopped. In order to stop this, we got a sand paper and tried to make the wheels as smooth as possible. This way, the car rolled more fluently and faster.