Launch Velocity of a Methanol Cannon
Conducted by Owen, Trevor, Noah, and Luke
Table Of Contents: Background,
Procedures, Diagram, Problem,
Hypothesis, Data, Conclusion,
Additional Links, Bibliography, Go Up
Methanol is a chemical (alcohol) with the chemical formula of CH3OH. Methanol, like most alcohols, is volatile. This means that it readily evaporates at normal temperatures. While in liquid form, this chemical compound is very flammable, and as a gas methanol can be quite explosive. Methanol is the simplest of alcohols, similar to ethanol (drinkable alcohol), it is colorless, volatile, flammable, and has a similar distinctive odor. However, unlike ethanol, methanol metabolizes into formaldehyde and formic acid when ingested in high quantities, DO NOT DRINK. Both formaldehyde and formic acid are toxic to the human nervous system, so regular lab precautions are necessary.
What is a methanol cannon?
A methanol cannon is a device that ignites methanol vapor inside a tube-like chamber, this combustion will then produce an outward force on a projectile, launching it away from the device, like a cannon.
What will we need to do this?
- 2, 1.5, 1 Liter bottles and a 20 fl oz bottle.
- Liquid Methanol
- Spray Bottle
- Bottle Caps
- Tesla Coil
- Stopwatch
- Nails
- Positive Attitude
- Log
What do we need to know?
- How to find vector components
- SUVAT (how to calculate velocity)
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1) Stab bottle with two nails an inch apart from each other for electrical arc.
2) Spray three squirts (approx. 2.46 mL) of methanol into bottle
3) Shake the bottle, saturate the chamber with vaporized methanol
4) Quickly cap bottle with intended projectile (cork)
5) Set methanol-filled bottle on �launch pad�
6) Touch tesla coil to one screw, (Spark ignites the methanol fumes)
7) Record distance with measuring tape
8) Open up and dry out the inside of the bottle
9) Once completely dry, repeat step 1-8 five times per bottle.
Record distance and time five times per bottle for each of the four different bottles.
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The question we are researching is: �What is the relationship between the volume of a bottle and the cap�s initial launch velocity? Is there a pattern in the different velocities? Is the velocity proportional to the volume of the bottle? The volume of the bottle is independent, the initial launch velocity of the cork is dependent, and the constants are; Amount of methanol, the cork used, the height launched.
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If we change the volume of the bottle that we launch the cork from, then by decreasing the volume of the bottle and keeping the amount of methanol combusted constant, we will find that there is a proportional volume to cork velocity ratio because as the volume decreases the energy released from combustion will have less room to expand thus increasing pressure and launching the cork at higher velocities.
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Link to .txt file: Data.txt
|
distance (m) |
time (s) |
# of squirts |
Vol of Methanol (mL |
Volume of Bottle |
Volume of Bottle (mL) |
Launch Height |
Launch Velocity |
Average Velocity |
|
8.3 |
0.8 |
3 |
2.46 mL |
20 fl oz |
591.471 |
0.72 |
10.38 |
10.358 |
|
8.1 |
0.78 |
3 |
2.46 mL |
20 fl oz |
591.471 |
0.72 |
10.38 |
|
|
7.9 |
0.78 |
3 |
2.46 mL |
20 fl oz |
591.471 |
0.72 |
10.13 |
|
|
7.7 |
0.75 |
3 |
2.46 mL |
20 fl oz |
591.471 |
0.72 |
10.27 |
|
|
8.4 |
0.79 |
3 |
2.46 mL |
20 fl oz |
591.471 |
0.72 |
10.63 |
|
|
7 |
0.75 |
3 |
2.46 mL |
1 L |
1000 |
0.75 |
9.33 |
9.218 |
|
6.9 |
0.76 |
3 |
2.46 mL |
1 L |
1000 |
0.75 |
9.08 |
|
|
6.7 |
0.73 |
3 |
2.46 mL |
1 L |
1000 |
0.75 |
9.18 |
|
|
6.9 |
0.75 |
3 |
2.46 mL |
1 L |
1000 |
0.75 |
9.2 |
|
|
6.6 |
0.71 |
3 |
2.46 mL |
1 L |
1000 |
0.75 |
9.3 |
|
|
6.1 |
0.69 |
3 |
2.46 mL |
1.5 L |
1500 |
0.76 |
8.84 |
8.504 |
|
5.6 |
0.65 |
3 |
2.46 mL |
1.5 L |
1500 |
0.76 |
8.62 |
|
|
5.3 |
0.63 |
3 |
2.46 mL |
1.5 L |
1500 |
0.76 |
8.41 |
|
|
5.4 |
0.67 |
3 |
2.46 mL |
1.5 L |
1500 |
0.76 |
8.06 |
|
|
5.5 |
0.64 |
3 |
2.46 mL |
1.5 L |
1500 |
0.76 |
8.59 |
|
|
5.3 |
0.66 |
3 |
2.46 mL |
2 L |
2000 |
0.78 |
8.03 |
8.146 |
|
5.1 |
0.63 |
3 |
2.46 mL |
2 L |
2000 |
0.78 |
8.1 |
|
|
5.2 |
0.63 |
3 |
2.46 mL |
2 L |
2000 |
0.78 |
8.25 |
|
|
5.3 |
0.65 |
3 |
2.46 mL |
2 L |
2000 |
0.78 |
8.15 |
|
|
5 |
0.61 |
3 |
2.46 mL |
2 L |
2000 |
0.78 |
8.2 |
|
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In this research study we were trying to find out if there was a direct proportional relationship between the volume of a bottle and the velocity of a cork launched from it. In this study we kept the same amount of methanol per launch (approximately 2.46 mL) and launched it from the same height (.75 m with a .03m variance). Our hypothesis going into the experiment was that by keeping those things the same and decreasing the volume of the bottle, then the initial launch velocity of the cork would increase because the energy released by the methanol combustion would have less room to expand and launch the cork at a greater velocity. For our tests we used four different sized bottles; 2, 1.5, 1, and a .591 liter bottles, and by maintaining the 2.46 mL of methanol, our average launch velocities were; 2L: 8.146 m/s, 1.5L: 8.504 m/s, 1L: 9.218 m/s, and our 20 oz (591.471 mL): 10.358 m/s.
In this graph the Launch Velocity (m/s) is on the y-axis and the Volume of the Bottle (mL) is on the x-axis. As you can see by the graph of our data, our hypothesis was correct in that as we decreased the volume the Launch Velocity increased. But our predictions of a proportional ratio between the velocity and volume was incorrect, we expected an almost linear pattern, but instead we notice a slightly hyperbolic curve (exponential decay). This suggests that as the volume of your bottle or container decreases then the velocity that the cork launches at is increased exponentially. By using our average velocity data points we can calculate the exponential regression of the data and find the function y=11.164 * .99983^x (y in meters/second). Theoretically with more data collection, increased accuracy and reduced uncertainty we could create a more accurate function to predict the velocity with any given volume of similar shape. There was a plethora of errors that occurred during the collection of data for this lab. We attempted to fire the cannon outside early on in the data collection until we realized that it was too cold outside for the gas to evaporate efficiently. This led to the possibility for inaccurate quantities of methanol being fired off at any time. The first prototype cannon that was built did not fire. Six feet long and made to shoot a tennis ball, both the quantity of methanol and outside temperature kept it from firing. Lastly, every time the plastic bottle cannon was shot, the explosion melted it causing the shape to be very deformed after numerous trials. This decreased the fidelity of the data collected by the cannon during the later trials.
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http://www.coolscience.org/CoolScience/KidScientists/oldpages/methanolcannon.htm
Nice succinct explanation!
https://sentynel.com/media/old/equations.html
SUVAT equations of motion (for reference)
https://www.youtube.com/watch?v=0aqH1JgmZ_4
Killer demonstration
https://pubchem.ncbi.nlm.nih.gov/compound/887
Compound Summary of Methanol
http://homeguides.sfgate.com/ethanol-vs-methanol-78394.html
Ethanol vs Methanol (for anyone who may conflate the two!)
https://www.youtube.com/watch?v=nY2nJbxayno
Our dumb demonstration video/Viper the Rapper �ballin�
https://acsundergrad.wordpress.com/2012/06/18/the-methanol-cannon/
An experiment we loosely modeled our own after.
https://www.youtube.com/watch?v=YuYmUGEkD_o
TuHS Physics Oaks Park Field Trip 2016 video
https://www.youtube.com/watch?v=OL6-x0modwY
Richard Feynman on the Scientific Method
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"Chemistry." Chemistry. N.p., n.d. Web. 04 Dec. 2015.
Giancoli, Douglas C. Physics. 6th ed. N.p.: n.p., n.d. Print.
"Methanol." Wikipedia. Wikimedia Foundation, n.d. Web. 04 Dec. 2015.
National Center for Biotechnology Information. PubChem Compound Database; CID=887, https://pubchem.ncbi.nlm.nih.gov/compound/887 (accessed Jan. 20, 2016).
"TCC." Methanol. .thechemco, n.d. Web. 19 Jan. 2016.
"The Methanol Cannon." ACS Undergrad Blog. Wordpress.com, 18 June 2012. Web. 04 Dec. 2015.
Zvi, Aaron. "Ethanol Vs. Methanol." Home Guides. SFGate.com, n.d. Web. 04 Dec. 2015.
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