Forums > Technical Discussion > Kid term poi physics. Help!

Posted: 2nd Mar 2005
Try relating it to planets orbiting the sun.

Or comets...

or maybe relate some moves to the pendulum of a clock?

Jo.

Educate yourself in the Hazards of Fire Breathing STAY SAFE!

Posted: 2nd Mar 2005
Talk about angular momentum as well as tension. Then move on to conservation of momentum and how that relates to the movement of the poi.

To do: More Firedrums 08 video?

Wildfire/US East coast fire footage

LA/EDC glow/fire footage

Fresno fire

Posted: 2nd Mar 2005
but i do't know any of that stuff.. that's the point.. i swing it it goes... i make it heavier, it goes a little easier, i make it lighter, it feels poopier, i put on tails it spins slower...
I dont' know WHY

I'll freely admit i'm really really stupid when it comes to this part.
jo- a nice idea but they want the physics behind why it does what it does.

that which yeilds is not always weak.

Posted: 2nd Mar 2005
Check out this thread:

[Old link]

really the best thing for you to do would be to google search for school/college physics / space classes on orbits and circular/pendulum physics.

Things like that are a good 'universal' interest to kids I think so good if you can relate it.

Also, these lessons will already be in tried-and-tested formats and I''m sure you could pick it all up in a couple of hours hard study.

Jo.

Educate yourself in the Hazards of Fire Breathing STAY SAFE!

Posted: 2nd Mar 2005
i read that thread before. It confused me more.

that which yeilds is not always weak.

Posted: 2nd Mar 2005
Theres really a lot of science going on with poi. Perhaps you dont really know about it now, but it would probably be pretty interesting (and easy) to research it and find out. Theres all sorts of enegy and momentum being used, crazy forces at play and such. Learning the physics of poi may even teach you a move or two... Who knows?

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Posted: 3rd Mar 2005
bah, physics, the bane of humanity...

(failed one of those tests today)

dip a dollar bill in alcohol, light it on fire, let the alcohol brn off, and explain that the dollar doesnt burn cause the alcohol burns at a much lower temp than the paper of the bill...

cept, that doesnt have much to do with poi...

but its still cool...

Educate your self in the Hazards of Fire Breathing STAY SAFE!

Posted: 3rd Mar 2005
ahh see draghkyre, thank you that helped!

that which yeilds is not always weak.

Posted: 5th Mar 2005
Yeah, if you look up some simple definitions of centripital force you should be well on your way.

Also, do the demo where you take a bucket of water and spin it while on a chain so that the water stays in the bucket.

Also, you can have the kids predict which way the poi will fly when you let it go. If you let it go at the top of the circle, most kids will think it will fly straight upwards but it actually flies at 90 degrees from that (So like straight forwards) because of the direction of the momentum at the time.

If you're cool, you find the force in the string by how fast the poi are moving and length of the poi and the weight of the poi.

Or, an easier one is, have a kid spin one as fast as they can for a set time. Then convert that to the actual speed of the poi. You can also see if a shorter or lighter poi is easier to get going faster. See if you can have a kid twirl a glowstick at over 100 miles an hour!

Hrm... lemme see how you'd do that.

1) Find the distance the poi goes in one rotation. That's 2*pi*(the length of the poi in feet)

2) Find out how many times the kid can spin the poi in 1 second (so like how many times he can spin it in 10 seconds divided by 10 or something).

3) Times the (Rotations per second in 2) by (Feet per rotation in 1) and you get how many feet per second the kid is spinning.

4) Times your "Feet per second" answer by 0.68 to find miles per hour. (Somebody double check me on that one.)

Example:
My glowstick was 1.5 feet long (18 inches) and I just spun it 72 times in 10 seconds.
1) The poi goes 9.42 feet per rotation.
2) The poi goes 7.2 rotations per second.
3) The poi goes 67.8 feet per second.
4) The poi goes 46 miles per hour.

Now my second trial:
2 foot poi, 60 times per 10 seconds.
1) 18.84 feet
2) 6 rotations/second
3) 113 feet/second
4) 77 miles/hour!

I bet I can get a longer poi going even faster!

*Someone smart please double check my math, I just woke up...*

Well, shall we go?
Yes, let's go.
[They do not move.]

Posted: 7th Mar 2005
Thanks NYC......anymore poi physics I would love to hear about. I do smart kids classes but my poi is better than my physics.

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