Our team of expert scientists were called on to verify just how awesome our potato cannon is.
Here are the findings:
| Attempt | Hangtime (s) |
| 1 | 8.53 |
| 2 | 7.74 |
| 3 | 8.39 |
| 4 | 6.94 |
| 5 | 7.24 |
| 6 | 7.86 |
| 7 | 8.14 |
| 8 | 7.25 |
| 9 | 7.63 |
| Average | |
| 7.746666667 |
But what about the height? Can we figure out just how high this thing is going based on how long it stays in the air?
The average hangtime for the potato projectile was 7.74 seconds (which feels like a while when you can’t see if it’ll land on your head or not).
With an understanding that objects accelerate and decelerate at 9.8 m/s squared (Mr. Burton rocks), we figured that it would take half of the parabolic trip to decelerate from leaving the cannon and then the other half to accelerate into the ground. For the average of the hangtimes:
1. The final velocity should be 37.926 meters/second.
2. 37.926 meters/second translates to 84.82 miles/hour. (0.0236 miles/second X 60 seconds in a minute X 60 minutes in an hour.)
3. The potato is crashing into the ground at faster than I am comfortable driving on the freeway.
This man, however, is crazy.
But…How high did it go?
4. 73.39 meters. That is the equivalent to 37 Booyors/240.71 feet/80.24 yards.
5. Our highest was attempt 1 (starch remnants start friction-ifying) at 8.53 seconds. That’s 89.13 meters/292.35 feet/97.45 yards/45 Booyors.
Yeah, buddy! End zone dance on Thanksgiving!
We are using a long plumbing pipe that fits snugly around a potato, a pipe that is a little wider but shorter to hold the igniter and the fumes. The igniter to create the spark is a starter from a barbecue grill and the Special Sauce is Auto Zone aerosol brake cleaner (only a tiny spritz is needed – you want a vapor and not a liquid). We use a PVC pipe as a ramrod, a la Killer Angels. We also were using compressed air to fill up the semi-vacuum created by the burning up of our precious gases.
Here’s the Excel spreadsheet (my father-in-law rocks) that we used to prove that the cannon is awesome:
Potato Projectiles
And now for the obligatory YouTube video with loud music and explosions.
Oh yes, and Leopard rocks. I will be working on my install. Here’s a sample:
Help me, father-in-law, you’re my only hope at Excel.
The Haiku
This reminds me of
the time my residents threw
chairs off the 8th floor.
Semi-related posts:
We need to experiment on different types of potatoes next. Red, Idaho, or sweet?
Nice choice on the music.
Thanks!
Without percent error calculations, the results mean NOTHING! See, I has learnded something in colleges.
My high school physics teacher used a fancy sprinkler-valve-and-compressed-air propulsion system for his cannon—I think the overall standard deviation of hang times might be lower with a more controlled form of propulsion.
Have you tried blocks of ice? Grab some scrap PVC pieces, fill with water, freeze, break off the ends, and you have essentially frictionless projectiles. “They work even better when you shave the ends to a point.” That’s the word on the street, at least.
Girard has the air compressor gun. I was considering giant rails of magnets to speed up nails and scraps of metal. As we get more consistent firing mechanisms, the more of actual weapons we create, I’m noticing.
Pingback: What to do in a non-Heroic world | Booyor’s BLOGgh!
Pingback: Booyor’s BLOGgh! » Like a Child