1. Describe your initial design. Describe how your design evolved into the one that you used. What did you alter on your original plan?
My original design was to craft an empty, plastic water bottle into a balloon car. First, I cut a small hole at the top to siphon the straw through the cap, leaving an excess amount of straw exposed through both openings. Then I taped two plastic straws to the bottom of the bottle, and slid in bamboo skewers to act as an axle. Correspondingly, I punched holes in four water bottle caps, large enough to fit the skewer and allow it to turn. Finally operating on the straw piercing through the bottle, I wrapped a balloon as tight as I can and taped it shut to deny any air to escape. This was my initial design. Although after testing it, this design was very stubborn and seemed oddly bulky for the balloon to move the bottle. The water bottle design failed the test, with only a maximum displacement of about 2. 7m or 270cm. I needed a material lighter and more aerodynamic for the balloon to make the car travel. I decided to use a thin piece of cardboard, which I cut out of an old, miniature cardboard box. Now instead of taping the axles onto the car, I shoved the straws and skewers into the openings between the cardboard. Resultantly, I used the same bottle caps as wheels, and taped the balloon-straw to the top of the cardboard. I am more satisfied with this cardboard design, thus hoping for it to travel 5m or more.
2. Describe the motion of your car. Did it run at a constant speed or accelerate constantly?
The motion of my car mostly ran at a constant speed. However as the car traveled farther and farther, the latex balloon seemed to deflate abruptly faster toward the end. In such manner the car gives the impression of accelerating near the end of its displacement, as if it's giving...
