Reflection

A. While making our balloon car, we had many instances when it did not work out and we had to find a way to solve the problems. I think the biggest problem that we ran into was the weight if the car. When we made our experimental design, the car weighed too much because of the tissue box on it and the axles we used. This caused the balloon to be not strong enough to move the car. We were able to solve this by making a lighter frame. Another issue that came up while making the car was finding the right wheels to use. In our "next generation" design we use CDs as wheels, but we could not get them to be perfectly straight, which caused the car to turn. We changed the wheels to smaller wooden wheels, that went faster, but we still ran into the problem of turning. We were not able to fix this problem and I think that was our biggest mistake. One more conflict that got in our way while making the balloon car was not letting too much air come out of the balloon. Because our car was so light, if we let out the air to quickly, the car would become unbridled. To fix this problem, we decided to use a bottle cap to some what restrict the air coming out. Though we had some conflicts that were difficult to overcome, we were able to create a successful balloon car. 

B.  Throughout the making of our balloon car, we also had many successful ideas and designing breakthroughs. Our most important concept was to make the balloon car out of balsa wood. The balsa wood was light in weight, easy to work with, yet sturdy enough to hold the car together. Another key idea that we had was within the making of the wheels. Originally we used markers for axles and CDs for wheels. after some tests we realized that there was too much friction between the axles and the CDs. When we used the wire from coat hangers as axles, we saw a huge improvement from the markers. The coat hangers had much less friction and allowed the wheels to travel farther. An additional idea that we had was to slow down the escape of the air from the balloon. When we did our first test, we noticed that the air came out very rapidly. This caused the balloon to flip backward and the car to not move much at all. We came up with the idea of cutting a small hole in a water bottle cap and inserting the balloon through it. Then we glued the cap to the car to hold the balloon in place. This worked excellently. The cap let the air out of the balloon at just the right speed. In the creating of our balloon car we came up with many great ideas that enhanced our car to be as magnificent as it is today.
C. 
Wendy- The most valuable part of this learning experience for me was being able to work successfully and getting to be really good friends with Emily. Creating the balloon car really helped me to understand the different aspects we had talked about in science class, and because Emily and I worked so well together, I'm really glad that we got to know each other more. As we worked through the project I realized you have to take a lot of things into account like air resistant and friction. I really enjoyed doing this project because it helped me visualize what we are working on in science, and because Emily and I became good friends:)

Emily- During this project I not only helped create an amazing balloon car, but I also got to do so with my new friend, Wendy. :) I learned a lot about motion and applying it to real-life situations in the balloon car project. Making our balloon car gave me a better understanding of how friction works. This project also helped me improve on constructing and engineering as well as teamwork. I've never really met Wendy before. I'm so glad that we worked together on the balloon car project. We were very successful throughout the creating of our balloon car and had plenty of laughs along the way. I benefitted a lot from completing this project. I not only discovered and learned a lot about motion, but I also became good friends with Wendy.
And her turtle and tortoise. (hence the name of our site)

Analysis

A. Newton's first law of motion states that an object at rest will remain at rest and an object that is moving at a constant velocity will continue moving at a constant velocity unless acted upon by an unbalanced force. Our balloon car followed Newton's first law. Before the balloon was released, the car was at rest; it was not in motion. The balloon car did not move until it was acted upon an unbalanced force. In this case, it was the balloon letting out air. When the balloon let the air out, it propelled the car across the floor. If no other forces acted on the balloon car, the car would have kept going forever. However, friction between the wheels and the floor was acting on the car. This causes the balloon car to eventually come to a stop.
B. The mass of the balloon car greatly affects its acceleration at the start. Newtons second law of motion states that the acceleration of an object is equal to the ammount of net force acting upon it divided by the mass of the object.  The less mass the car has, the faster it will accelerate. The more mass the car has, the slower it will accelerate.
C. Momentum is the product of an object's mass and velocity. The more momentum an object has, the harder it is to stop. This means that objects with more momentum have a higher inertia, or a higher tandancy to resist change in motion. The more mass and velocity an object has, the more momentum it has. If the momentum of the balloon car is very great, the car will continue to move even after the balloon has deflated. Of course, friction is acting on the car, so the balloon car will eventually stop. If the balloon car has little momentum, it will not continue to move much further after the balloon had deflated. This is because the momentum is not strong enough to keep the car moving.
D. Newton's third law of motion in its simplest form is: for every action there is an equal and opposite reaction. This law applied to our balloon car as it does for everything on the planet. The first object is the balloon which caused the car, the second object, to move forward by the air pushing out and back. The force relates to Newton's first law of motion, (an object at rest will remain at rest and an object that is moving at a constant velocity will continue moving at a constant velocity unless acted upon by an unbalanced force), because the force that is being acted on the balloon car is the air bing pushed out of the balloon.
E. The three different types of friction are sliding friction, rolling friction, and fluid friction, all of which were involved with our balloon car. Sliding friction was used between the axle and the wheel, so we had to make sure there was as little friction as possible. Rolling friction was used between the wheels and the floor, so we had to make sure the wheels were smooth enough to keep rolling. Finally fluid friction was used from the air com in out of the balloon so we had to make sure there was enough air coming out to create a strong enough force for the car to move.

Second Trial!!

Our second trial defiantly did not go as good as our first. We decided to use to small wooden wheel instead of the CD's, because they had less friction between the wheel and the axle, which made the car go faster. Our mistake with using the wooden wheel was that we still did not have them on perfectly straight. Because of this there were two problems: the car could easily turn, and it had a slight up and down motion to it. When we tested the car back at home, the car did not urn as badly as it did in the school's hallway, but we did give it a few taps at home to make it go straight. If our ballon car had continued to straight in the hallway, it probably could have covered a farther distance. Because it took a sharp turn however, on the second trial of our balloon car test, we only went 3.3 meters:(

Second trial at home...

We tested Philip IV one more time just to see if we had adjusted the wheels right. It was hard to get them to be perfectly straight because we had not drilled the hole in the exact center of the wheel, and the beads on the axle that kept the wheel from sliding off, could have maybe been a bit tighter.

First real test at home...

Once  we knew that the wooden wheels were most likely going to work better than the CD wheel, we decided to try and make the wheel more precise... which meant we had to make the holes in the wheels bigger, since we only had six wooden wheels. We needed a different axle since the hole was going to be bigger, so we thought of using a nail for the axle. This was a great idea because it was the prefect size for such a small wheel, and we could cut it down so it wouldn't be too heavy.

First test at home...

Our first test with the new wheel was fortunately not an epic fail:D! There was a problem with car car turning, but we were using a thiner piece of metal for our axle, and had not taken the time to really make sure the wheels were straight... this became a problem for us in the future.

OOOPPS!!!

We tried to make the hole in the wheel big enough to use a nail as an axle... that failed!!:P