Experiment for Schoolchildren Edutainment 3

[Jabberwocky]

I think this is the best forum, but please recommend others if you can think of a better one:

There is a program for National Engineers Month (February in case you forgot) that involves going to local schools and presenting on your job and engineering careers in general - drumming up excitement for the next generation of techies. A large part of the presentation is an 'experiment' to offer hands-on experience to the kids and make them think about engineering outside of their normal routine. You only have about 30 minutes, and obviously monetary resources are limited.

I'm aiming at middle school, but high school level is acceptable too - does anybody have any bright ideas?

 

[kacarrol]

I'll chime in on what a couple of other people said. If it blows up it's really interesting. I've had to do a couple of these myself.

You could do something on steam condensing. There is a cool video of a rail car that collapsed after it was steamed out. You could play that and then do an in-class demonstration by heating 1 tbsp of water in a pop can until it boils then turning the can upside down into a bath of ice water (the can collapses quite dramatically). There should be pictures of tanks that have collapsed under vacuum on the net. That's all mechanical!

Collapsing popcan:

http://www.cmste.uregina.ca/Quickstarts/popcancrushing.html

Imploding rail car:

http://www.acusafe.com/Incidents/Collapse_Steam/incident-collapsingsteamOilCar.html

(there's a video somewhere on the net but I can't get video at work)

Although it's not destructive you could get tanks of water and have them design a neutral buoyancy item by using foam and paper clips.

http://teacher.edmonds.wednet.edu/brierterrace/spresho/documents/neutral_bouyancy.docx

This website is awesome:

http://www.engineerguy.com/videos.htm

I love the quartz watch video.

Or you could do a demonstration of automata:

http://www.keithnewsteadautomata.com/forsale/contraband-cat

This thread has been great, I'm adding all of these ideas to my collection!

K

 

[kacarrol]

Or if you have a bit of space and can get things a little messy you can make a non-newtonian fluid (cornstarch and water) and demonstrate it's properties (have them walk across it vs standing in it.

http://www.stevespanglerscience.com/science-video/walking-on-water

 

[Ashereng]

Something simple like an electro-magnet: need batteries (C, 9V, etc), wires, various carbon steel nails, bare copper wires.

Batteries in series to boost voltage. Some big nails to demonstrate strength of the electro-magnet.

The experiment is available on web I believe.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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[MiketheEngineer]

Show a re-run of "Pumpkin Chunkin" and review the physics involved...

 

[SnTMan]

We solved a problem in fluid dynamics that has always interested me as to building a working model.

It involved finding (as I recall) the max range of a free jet exiting the side of a tank of fluid. Due to the form of the governing equations it had two solutions, one near the bottom, one higher up. It would, I think, make an interesting model and demonstate the physical reality behind the math.

Students would need to be at a high enough grade level to get the math, of course, which is not really that advanced. After all, I got it.

Pretty simple equipment, some kind of a container, a drill and drill bit, some water, some pencil and paper. Add a small pump and battery and have a "water sculpture". I'll do this when I get all that more important stuff done

Regards,

Mike

 

[SomptingGuy]

When I was a lot younger, I found that making electric bells from copper wire, bits of meccano and batteries was always good fun. The next extension is to make one of those steady-hand games, where the (home made) bell goes of if you accidentally complete the circuit.

- Steve

 

[rb1957]

yeah, but that was before twitter and the momentary attention span prevalent these days. the more flash and bang (shock and awe?) the better !

 

[csd72]

get a very flexible but flat ruller, ask them to guess which orientation it will be stronger and which it will bend more and then hang a weight from the middle to test it.

Good demonstartion of buckling.

You can also turn it around to act like a column to show the effect of reducing the effective length.

I saw a load test on an egg once I think it took 300kg. But that would be hard to simulate in a classroom.

Also get them to build a tower with a pack of cards.

You can also demonstrate post tensioning with a bolt and a couple of blocks.

 

[Jabberwocky]

Thanks for all the links and discussion, I'll dig around and see what I can find. Unfortunately I think some of the more...energetic exercises might get us banned from the school (not that it wouldn't be awesome and make a big impression on the students).

Definitely leaning towards destructive testing of something, the toothpick tower/bridge is an old standby but you're right the time-limit is so tight there's probably not time for a second iteration, which is where actual learning could happen.

 

[jmw]

Are you expecting to be invited back?


JMW

http://www.ViscoAnalyser.com

 

[moltenmetal]

A nice simple demo would be to to take the same limited piece of material and deploy it to span a distance between two desks in two different ways: as it comes, and in an "engineered" form (i.e. a truss or I beam etc.) Test them both to failure- a bucket and nice dry sand etc. For a reasonable distance and a reasonable load to failure, a 2x4 is probably too much material...

 

[KENAT]

I had the same thought as moltenmetal a few weeks back.

Maybe take a few pieces of 'poster board' or similar thin cardboard.

something that will just support it's own weight over say a 24" span. Load it with small weights - or even better something entertaining to the kids like lego men or something - until it fails.

Then produce one rolled into a tube and repeat.

Then say one folded into a box beam and repeat.

Then maybe folded into an I beam and repeat.

You need to be careful to use little or no tape or adhesive or the kids will think that's why they're stronger.

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[jmw]

Here's another non-newtonian video:

http://community.micromotion.com/Iain Gordon/videos/60

JMW

http://www.ViscoAnalyser.com

 

[Jabberwocky]

Success! The presentations were on Wednesday, and despite a freak blizzard everything went (almost) according to plan.

The experiment was about bone fixation since that's what my company does, I had a model humerus bone split in half with popsicle sticks, dowels, and electrical tape to fix it back together. Each part had a cost associated with it, and they had to come in under a fixed budget as well. The constructs were tested on a 3-pt bend fixture we brought from in from the lab, highest load to failure and most efficient solution teams won candy bars (and bragging rights).

It took just about the whole class to work through it, although one or two groups were fast enough to get a second iteration in - all of which were 10-20lbf stronger than their first. It was also interesting to see even at that age you could tell the techie kids from the rest.