Friday, February 24, 2006

Ethanol and Flour (with video!)

Our plan for today:

1) Play with LEGO Mindstorms set
2) Blow up flour

Flour, you see, is quite flammable in airborne-dust form. So, we got into the Physics classroom and took out a tin popcorn can, some flour, and the LEGO kit. JP immediately got to work on a robot, and we started looking for key ingredients in our experiment.

We got a candle and some matches. We went outside, put the candle in the tin, and lit it. We tried dropping some flour in and we tried blowing on the layer of flour at the bottom of the tin. All was to no avail; we got no reaction. We went back inside and determined we needed a bigger flame. Vivek left to get a bunsen burner and came back with some ethanol. We tried adding a bit of that to the candle, but to no avail. A small crowd gathered but dispersed after multiple failures.

We still needed a bigger flame -- and less wind. We went back inside again and watched this video for inspiration. New strategy: we put the tin on the ground, soaked a piece of paper with the ethanol, dropped it in the tin, lit a piece of paper, dropped that in, and had a nice little fire going. We then sprinkled flour on -- a little bit at first, and then some more.

We had no real video camera, so we used the camera rocket's nose. Quality isn't great, and you don't see some of our best ones, but it's better than nothing! :)



Next meeting we'll be doing this again, since almost everyone had left by the time we succeeded. Maybe we'll get a slightly bigger boom. :)

Egg Drop Aftermath: Autopsies

As today marks the two-week anniversary of our momentous egg launch contest, I thought I'd fill you in with a little more detail concerning the fates of our three rockets.

Vivek & Co. Potato Gun

Vivek's group's egg was, needless to say, completely obliterated. The vessel carrying it was just as wholy annihilated. The egg formed a small crater in the sand of the baseball diamond (see image at right).

The potato gun suffered some trauma of its own. As you can see in the video, Mr. Clippenger screwed the cap on very thoroughly. Unfortunately, this resulted in the cap being stuck shut. Fortunately, the issue has been resolved. :)

In addition, a small black film canister was found in the barrel of the potato gun. My hypothesis is that the canister was somehow part of Vivek's team's contraption, although I can't be sure.

Peter & Co. Long Rocket

Peter's group suffered a sad blow when their rocket's engine shot up through the body, through the egg, and forced its way out the top. The rocket itself never left the ground. The egg, found shortly thereafter, had a scorch mark and had been shattered, albeit not as completely as Vivek's.

The body shows few signs of trauma. One fin had broken off, although it is unclear how. The fin was found some time after the competition had concluded for the day, and was splattered somewhat with egg. The initial assumption was that the fin had come from my group's stubby cup rocket, but was changed after witnessed the missing fin on Peter's rocket.

The upper tube shows a slight rip in the cardboard, although it is unclear whether or not this was a result of the engine malfunction. The parachute, which (using the hole in the middle) had been slipped down over the nose of the rocket prior to launch, showed slight burns and fusing, although it is again unclear whether it was a recent injury.

The interior of the body shows no readily visible signs of scorching.

Toph & Co. Cup Rocket

The rocket appeared to launch well. The top portion separated as it was supposed to; the second stage opened up like a clamshell and deployed the parachute, just as it was supposed to. But upon landing it was found that the cup had split along the side and was oozing egg.

As it was a relatively soft landing, it is not clearly understood why the cup split. It is possible, from examining the video, that the rocket may have hit a tree branch. This would explain the strange crack, which we believe could not have resulted from that landing.

A second idea is that the stresses of liftoff cracked, compressed, and/or split the egg and cup. The parachute ejection charge that separated the booster phase from the carrier phase may also be to blame.

Mysteriously, the whereabouts of the remains of the cup rocket remain unknown. The video depicts Mr. Clippenger bringing it off to one side, but it is unclear exactly what he did to it or what happened thereafter.

Conclusion

Our inaugural egg launch/drop contest was not a success. However, it was certainly entertaining and educational. We look forward to a second contest sometime next year. That contest will hopefully be both better documented and more carefully analyzed. This is the Beaver SCIENCE and Engineering Club, after all. We should attempt next time to calculate such properties of each launch as velocity, distance, height, and more.

Friday, February 17, 2006

Egg Drop Aftermath: Update

As you saw in Vivek's last post, our thrice-delayed egg drop contest was finally concluded last Friday. I think it was a big success, at least in terms of entertainment value. :)

The only bad thing that happened all day was the final rocket getting stuck in a tree. I am now happy to report that Mr. Clippenger has managed to retrieve the rocket, and it seems to be in pretty good shape, despite its week exposed to the elements (including snow, and lots of it).

You can see in Vivek's video that it was hanging very precariously from the end of a thin branch. It actually fell from that spot even before we went back inside, only to land more securely in the neighboring pine. Fortunately, it's fine now. I was prepared to blast the tree with a potato...

The stormy edge of the silver lining to the stormy cloud of landing-in-a-tree-ness is that, well, we forget to start the camera rolling. :( Hey, don't blame us -- it was freezing out there, the wind knocked over the launch pad and rocket if you waited more than 30 seconds, it was our fourth launch of the day, and we were eager to go back inside and eat lunch. But the recovery means it shall live to film another day -- the meeting after next, perhaps?

Speaking of last meeting, the consensus at this point is to break out the Mindstorms and play around. Stay tuned.