Science Component - Design Elements, Research, and Process

Design plan: We concluded that the way we designed our tennis ball cannon was the most efficient way because it supported the cannon and its chambers.

Launch Angle: We chose to angle our cannon at 45 degrees because we determined that any angle below 40 degrees would shoot too low and hit the ground quickly, while an angle any higher than 50 degrees would travel straight up and not reach its full capability in shooting range.

Gas Law Used: We used Gay Lussac’s Law because it states the pressure of gas is always proportional to the temperature while the volume remains constant. In our project, the temperature of the ethanol will increase when we light it, therefore the volume of its gas will proportionally increase. This increase in volume will launch the tennis ball out of the cannon.

How does this reaction happen: When Ethanol and Oxygen react, they combust and create pressure to launch our cannon. The chemical equation for the combustion of Ethanol Oxygen is:

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O 

Difficulties in Construction: When constructing our cannon, we had difficulties getting the cannon to stand at the proper angle and height. On our first try, we cut the lids of the tennis ball cans and taped them to the bottom of the cannon, but because of our limited materials, we were unable to create the right angle and height. In the end we decided to the remainder of silver wire from the tennis ball container because it was easy to adjust to the right height and provided more stability.

Construction Tools/Materials and Procedures:

Materials:

·      Two tennis ball containers with tops

·      An 18 inch piece of tape

Tools:

·      Scissors

·      Marker

·      Ruler

·      Protractor

Procedures:

1. Measure the first tennis ball container 4 inches above the bottom of the bottle. Then draw a second mark 4 inches after the first mark. Cut the first tennis ball container at the second mark from the bottom. Then stab a hole about three inches from the bottom, to allow the gas to escape. Repeat this same procedure for the second container. Exception: Do not cut a hole 3 inches above the bottom of the bottle in the second container.

2. Next cut the container where the first mark is (from the bottom) and then cut the second mark (which is at the top of container) off. Repeat the same steps for the second container.

3. Cut base of the second tennis ball container. After you finish cutting both containers, you should have a top piece, a middle section (that you cut from), a bottom, and half of the bottom end of the first cannon. Put them all together. Note: Cut the wire on the second container, for later use.

 4. Once you have each piece in the correct position, tape the pieces together with duct tape, to secure them for when they are fired.

5. After taping the pieces together, measure and mark 45 degrees from the bottom of the cannon. Insert the base of the cannon (the half-bottom of the first cannon), underneath the end of the cannon.

6. Finally, cut the piece of silver wire (if not done previously) and insert it underneath the cannon so that it aimed at the proper 45 degree angle.