Sunday, January 9, 2011

Elements of Our Cannon

Design Plan: Our design is to have one canister as the base and the other serving as the combustion chamber. We will cut the shape of the top canister so it will be more stable. The combustion chamber will be attached by tape and be fixed at a 45 degree angle. The ignition hole will be on the bottom half of the right side. We think that the ethanol will set more in the top of he canister so if we but the hole lower that gas won't escape. We will just have to put the splint higher into the canister when we are ready to fire that cannon.

Launch Angle: We decided to have our launch angle be a fixed angle at 45 degrees because we believed that with this angle we would be able to get the ball to go far and high without it being too much of either. It also gives the ball some time in the air to travel farther because it won't be traveling too close to the ground.


Gas Law Used: Gay-Lussac's law says that the pressure of a gas is directly proportional to the kelvin temperature if the volume is held constant. In other words when the temperature goes up the pressure goes up and vise-versa. With our cannons the volume will be held constant because that canister's volume does not change. At time of ignition the hot splint will ignite the ethanol gas and the temperature in the canister will rise very quickly so the pressure has to do the same. This causes the nerf ball to be shot into the air.

Math Component/ Formula and Expected Results: We used the range formula  of R= (Vo2sin 2q)/g. R is the range of the nerf ball, the V is the initial velocity (estimated), q is the launch angle, and g is gravity which is always 32.2 meters per seconds squared. We estimated our initial velocity to be 10 meters per second and multiplied it by sin 2(45) and divided that by 32.3. The answer came out to be about 3.1 meters but after we converted to feet it was 10.2 feet.

How Does The Reaction Happen? The balanced chemical formula for this reaction is  C2H5OH + 3O2 ® 2CO2 + 3H2O The CO2 in the reaction build pressure in the canister and causes the nerf ball to be shot from the cannon. Difficulties in Construction: Our group really didn't have any difficulties in the actual construction process since we had though out and sketched the design several times. We worked well together and I dont' think I would change anything about the way that we constructed our cannon.

3 comments:

  1. Good job using skills you learned from every class(:

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  2. This is really good!! lots of good info and great pictures!!! :D

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  3. I like it!! Those are all the things we learned from class, and are incorporated in the project well. You dont need to worry about anything haha

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