Group Work/Science Work Part:

What would you do differently:

            If I could do anything different with my cannon project, I would have started earlier on the history part of the blog. Also, I would have put a cap with a small hole half way down our cannon, to increase the pressure so the NERF ball would go further.

Launch angle/choice justification:

We chose a 45 degree angle for our cannon because we believe that 45 degrees is the highest trajectory for our cannon, without it firing strait up.

Expected/actual results:

(Due in March)

Justification for our design:

            We choose our design because we believe that our design is the most efficient design that you can make with the provided materials; because of our reinforced barrel, we can build up higher pressure without an explosion.





 

How pressure, temperature, and volume (gas laws) play a role in our design:

            In Gay Lussacs law, volume is constant and the pressure of the gas is proportional to the temperature. In our project, when we light the ethanol, it creates CO₂ and H₂O while also releasing energy. The energy increases the temperature in the cannon which causes the gas to expand, raising the pressure. This increase of pressure builds in the cannon until it pushes the projectile (a NERF ball) out of the cannon.

Chemical Equations for the combustion of ethanol in oxygen:

C₂H₅OH+3O₂=2CO₂+3H₂O

Difficulties in construction:

            In constructing the cannon we had difficulties getting our cannon to stand upright. Our first try was cutting the lids of tennis ball cans and tapping them on the ends of the cannon barrel, but this did not work. We then decided to take a piece of metal from the end of one of the tennis ball tubes and first cut it. After that we bent it into a “U”. Then we taped this upside down to the bottom of the cannon’s barrel.