Chief Delphi

Chief Delphi (http://www.chiefdelphi.com/forums/index.php)
-   General Forum (http://www.chiefdelphi.com/forums/forumdisplay.php?f=16)
-   -   Disk tendencies (http://www.chiefdelphi.com/forums/showthread.php?t=111283)

Camren 15-01-2013 07:07

Disk tendencies
 
Alright I am hoping that teams have a barrage of data to complement what our team has on the subject

subject: Does the frisbee tend to land right side up, or upside down?

out of 30 disks our team found all were up

though 3 times out of 5 when we tossed it up like a coin it would land upside down.

Tom Line 15-01-2013 07:26

Re: Disk tendencies
 
The frisbees are, in essences, a gyroscope. Their spin resists flipping. You can test this by bouncing them off the wall. Most will land upright. However, I would always design for the worst case.

Thrown like a coin, they should tend to land upside down - the solid top and open bottom moves the center of gravity to the top of the frisbee, and without the spin they have nothing to counter balance it.

However, I expect with the coriolis effect of the earth, teams in Australia may find this is all backwards from what they expect. That will make it a very difficult challenge for them.......

Spirator 15-01-2013 09:08

Re: Disk tendencies
 
Quote:

Originally Posted by Tom Line (Post 1215640)
The frisbees are, in essences, a gyroscope. Their spin resists flipping. You can test this by bouncing them off the wall. Most will land upright. However, I would always design for the worst case.

Thrown like a coin, they should tend to land upside down - the solid top and open bottom moves the center of gravity to the top of the frisbee, and without the spin they have nothing to counter balance it.

However, I expect with the coriolis effect of the earth, teams in Australia may find this is all backwards from what they expect. That will make it a very difficult challenge for them.......

We hadn't considered the impact of the Coriolis effect on our shooting. How much of an impact would this have? We're going to Honolulu to compete later this year.

Mark McLeod 15-01-2013 10:06

Re: Disk tendencies
 
Quote:

Originally Posted by Spirator (Post 1215687)
We hadn't considered the impact of the Coriolis effect on our shooting. How much of an impact would this have? We're going to Honolulu to compete later this year.

Just remember to take your Coriolis effect with you. There's no going back for it later.

akoscielski3 15-01-2013 10:56

Re: Disk tendencies
 
When we were testing, the day of kickoff, we threw a frisbee at a wall 50 times, of which 5 landed upside down. Therefore about 90 % were landing right side up. This was throwing at a brick wall, with the frisbee only about 5 feet off the ground.

F22Rapture 15-01-2013 11:11

Re: Disk tendencies
 
I was under the impression that the Coriolis effect was almost completely negligible in small-scale systems. Similar to how it isn't actually responsible for water's rotation around a sink or toilet (they're actually designed that way), the curve of a frisbee is almost exclusively determined by the angle it was thrown at, and from which direction.

It's one of those bad, only 1% true explanations that caught hold in popular culture and won't let go. Similar to how it's still taught in lower-level science courses that oil and water don't mix due to density, when in actuality it's because of the polarity of the molecules.

Remember that the Coriolis effect is nothing but the difference in the speed of earth's rotation across the 11 inches of the frisbee.... that's an infinitesimally small amount. It's not going to affect anything at the scales we're talking about.

http://www.scientificamerican.com/ar...site-direction
http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html
http://www.snopes.com/science/coriolis.asp
http://science.howstuffworks.com/sci...t-baseball.htm

mikemascot 15-01-2013 15:42

Re: Disk tendencies
 
Quote:

Originally Posted by Tom Line (Post 1215640)
However, I expect with the coriolis effect of the earth, teams in Australia may find this is all backwards from what they expect. That will make it a very difficult challenge for them.......

well they would definatley notice a change in flight

Bryscus 15-01-2013 16:23

Re: Disk tendencies
 
Quote:

Originally Posted by F22Rapture (Post 1215742)
I was under the impression that the Coriolis effect was almost completely negligible in small-scale systems. Similar to how it isn't actually responsible for water's rotation around a sink or toilet (they're actually designed that way), the curve of a frisbee is almost exclusively determined by the angle it was thrown at, and from which direction.

It's one of those bad, only 1% true explanations that caught hold in popular culture and won't let go. Similar to how it's still taught in lower-level science courses that oil and water don't mix due to density, when in actuality it's because of the polarity of the molecules.

Remember that the Coriolis effect is nothing but the difference in the speed of earth's rotation across the 11 inches of the frisbee.... that's an infinitesimally small amount. It's not going to affect anything at the scales we're talking about.

http://www.scientificamerican.com/ar...site-direction
http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html
http://www.snopes.com/science/coriolis.asp
http://science.howstuffworks.com/sci...t-baseball.htm

I may be WAY off base here, but I believe it was a joke...

- Bryce

F22Rapture 15-01-2013 17:20

Re: Disk tendencies
 
Quote:

Originally Posted by Bryscus (Post 1215936)
I may be WAY off base here, but I believe it was a joke...

- Bryce

That may be correct :P

gabrielau23 16-01-2013 23:24

Re: Disk tendencies
 
Quote:

Originally Posted by Tom Line (Post 1215640)
The frisbees are, in essences, a gyroscope. Their spin resists flipping. You can test this by bouncing them off the wall. Most will land upright. However, I would always design for the worst case.

Thrown like a coin, they should tend to land upside down - the solid top and open bottom moves the center of gravity to the top of the frisbee, and without the spin they have nothing to counter balance it.

However, I expect with the coriolis effect of the earth, teams in Australia may find this is all backwards from what they expect. That will make it a very difficult challenge for them.......

Somebody please tell me this is a joke. The diamter of the earth is 4.18508e7 feet. The frisbee is about one, when compared with that. So just like taking a limit, it's effectively zero, or effectively infinity, depending on which way you're putting the ratio. Either way, it doesn't make sense. And I promise I will post "lololololololol" if I got trolled really hard.

Wayne Doenges 17-01-2013 14:26

Re: Disk tendencies
 
Quote:

We hadn't considered the impact of the Coriolis effect on our shooting. How much of an impact would this have? We're going to Honolulu to compete later this year.
Also remember that since you will be in the northern hemisphere, you will need to spin the frisbee backwards from what you are spinning it down under :D
This has been a public service announcement. We now take you back to your regularly scheduled posts.

FrankJ 17-01-2013 14:29

Re: Disk tendencies
 
Are you close enough to Australia that you will have to throw them upside down?

Tom Line 17-01-2013 14:31

Re: Disk tendencies
 
I never considered how inverted gravity would affect climbing the pyramid while in Austrailia. Letting yourself down rung by rung seems much easier than what we have to do up here in the States.

Mark McLeod 17-01-2013 14:51

Re: Disk tendencies
 
Quote:

Originally Posted by Tom Line (Post 1217301)
I never considered how inverted gravity would affect climbing the pyramid while in Austrailia. Letting yourself down rung by rung seems much easier than what we have to do up here in the States.

Yea, but getting it back to the floor safely and making it stick is probably much harder.


All times are GMT -5. The time now is 06:56.

Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi