Submarine Model-building Reflection

Drawing of 'submarine' sinking

Describe any design ideas that you had which did not work as expected.

One of the designs we made had two bottles duct taped together. One of the bottles was filled with water and sealed with the cap and clay, and the other bottle had a balloon connected to a tube. The balloon was inside the bottle, and the tube was outside for blowing into. This design didn't work because there were no holes, and blowing into the tube didn't make the figure float as we wanted it to.

Describe any design ideas that you had which did work as expected. 

My successful bottle had clay at the outside bottom of it, and the clay and bottle was held together with rubber bands. There were holes on each side of the bottle to the right and left, and there was a balloon inside the bottle, and a tube attached to the balloon that was outside of the bottle for blowing into. This model was successful, because when you lay it on top of the water, water goes into the bottle through the holes making the 'submarine' heavier, and finally sinking. Then you blow into the balloon, water pushes out of the holes to make room for the expanding balloon. Finally, the figure becomes light enough to float again.

Describe at least two ways that your model works like a real submarine. Describe at least two ways your model works differently than a real submarine.

Similarities

1. They both can float and sink.
2. Both figures suck in and push out water to sink and float.

Differences

1. People in submarines don't blow into a tube to make the submarine float, because compressed air pushes water out of the submarine. We had to blow into our submarine models because we needed an easy way to push water out.
2. Real submarines don't need clay to make them heavier, because the submarine is heavy itself. 

Did you ever feel like you were not going to be able to successfully modify the plastic bottle to make it dive and float like a submarine? If you did not give up, what strategies helped you persevere and keep going? 

Yes I often felt like I wasn't going to succeed in the making the bottle float and dive, because when we first started our experiment, we didn't really use our past knowledge on sinking and floating, we didn't really know where to start, and we just did random things to our bottles. At first I highly doubted it was possible to make a bottle continuously sink and float without touching the bottle, but then a group of boys next to us succeeded which made me realize that it was possible, and that we could do it if we thought about what we were doing, and if we though scientifically.

If you worked with a partner, describe what contributions each of you made to the project.

Sia and I both made separate bottles, but we shared equipment and ideas. We worked separately because we each had different ideas that we thought would work, and each of us wanted to try both ideas.