Balloon Car Project

Kaia Anderson, Courtney Spang, Alex Elshaw, and

Zac Repinski!Hour 5

About Rough Draft One

• For our first rough draft, we didn’t think outside the box very much. We used CD’s because we knew they were round, and a Coke bottle because we thought it was light. But we realized the bottle wasn’t very dynamic and it would be hard for the balloon to power all the weight of the CD’s and bottle! So we made a new draft.

About Rough Draft Two

• For our second rough draft, we made many improvements. First we changed the body of our car to a piece of cardboard, taking off lots of weight and making it more aero-dynamic! We also put a straw in the balloon to add more pressure, so the car would go further. But we still wanted to make a few more changes!

About Our Final Draft

• For our final draft, we made some minor changes. We added a skewer in the straw so the caps could spin easier. We made the straw longer so it went off the cardboard. This allowed the air to push against the ground so the car could travel better. We placed a rubber band around the balloon so it could stay in place, and we could blow it up thru the straw. Before we built our car we made sure it was going to be aerodynamic enough. This played a large factor in what we chose to build our car out of.

CAR INFO~Worklod

• Our car went 7.2 meters

• It weighed 23 grams.

Our group worked together and came up with great ideas, but some did more work then others. Our car wasn’t the prettiest, but the presentation worked! It was creative enough, while still aerodynamic!

Top View of Car

Under-side of Car

Side View!

How the laws applied to our car• Newton's 1st Law: I knew that the car would not move unless another unbalanced force

acted on it, and that other force was the balloon. The force the balloon has is not very great(in comparison to other things) so then I realized my group would have to build a car that was light, light enough for the balloon's force to move it. To increase the force from the balloon, my group put a straw inside the hole of the balloon. This caused a greater force from the balloon as the air comes out of the straw, therefore accelerating and pushing our car faster. To reduce friction on the ground we used circular cap wheels. To reduce friction within the wheels we used skewers and straws as axels, to maximize smooth rotating ability.

• Newton's 2nd Law: Continuing on from the first law, mass and net force are directly proportional to acceleration. A heavier car would take more force to get going, while a lighter car will go with less. Doubling the mass will cut the acceleration in half, or cutting the mass in half will double the acceleration. Knowing this, I knew our car must have a small mass. Otherwise in a heavy car all of our balloon's force would be working to get the car to accelerate, instead of just pushing it along. In our first draft we had a plastic coke bottle and CD's as the body and wheels. To lighten our mass we changed the body to a thin piece of cardboard, and the wheels to water bottle caps. By doing this we made our car accelerate at least twice of what it would have with the coke bottle and CD's.---Kaia Anderson

Laws cont.• Newton's 3rd Law: When we were building our car we knew that as our balloon pushed out air, and

exerted force, that there would be an equal opposite force acting on the car also. That other force would be air. Especially since we were going to test our cars outside I knew the car had to be aerodynamic. In our first draft we were going to add a cone to the car, but since our design changed we had to come up with a new idea. We taped the balloon in place so it didn't get pushed around by the air too much. We also taped the straws onto the bottom of our car, leaving space so that air could go underneath the car, and not hit up against it. We changed our body to a piece of thin cardboard, which is not as much mass for the air to push up against. The cardboard had a slight curve up in the middle, making it even more aerodynamic. Our car was small enough to slice through the air and let it pass underneath or above with ease.

• Alignment Forces: As we designed our car we wanted to make sure the net forces acted in the same direction and the car went straight. Since our wheels were bottle caps, they had a slight curve in them. But we made sure they were as straight as they could be before we tested the car. We taped the balloon in place so it would blow in one direction. The air outside took our car a few different directions each time! The straw was also taped so it didn't move as air was released from it. Our skewer axel spun around straight each time. We tested these things so our car would go straight!—

• *If I could redo one thing one our car I would put new wheels on it. The wheels were not perfectly round and had to be moved each time so they would sit straight. If we had found smoother round objects to use I think our car would've gone even farther! But I was still very happy with our 7.2 meters.---Kaia Anderson

Kaia’s Reflection• I learned many things about motion in the process of doing

this project. I now know that Newton’s Laws have great affect on every object, including our car. We had to take this into great consideration as we built it. I learned that we had to build our car out of materials that are light in weight, small, and aerodynamic because this would give us the best car. Our car went 7.2 meters so I think we did a good job of putting all of Newton’s Laws into affect when we built it. If I could change something about our car it would be the wheels. The wheels did not roll as easily as we would’ve wanted. Another thing I would change would be the balloon structure. I think we could’ve taped in on more secure, to help our car roll straighter.

Courtney’s Reflection

• Our car went five meters which was the goal. I thought our car went pretty far, but if I could’ve changed something I would’ve liked to find a way to make our car go striaght. Our car kind of went sideways so it didn’t go as far as it could’ve.

Alex’s Reflection

• My groups car went 7.2 meters and the minimum requirement was 5 meters. WE did use light weight objects but if I was to do this project again I would definitley make some improvements. I would’ve used different wheels because we used water bottle caps and if we would’ve used wheels that has less surface area, then there would’ve been less friction between the wheels and the ground.

Zac’s Reflection

• I was happy with how my groups car performed. It did go pretty far but I think if we researched better ways to make our car role easier then it could’ve used different materials that made less friction between the wheels and the ground and also the moving parts.