# 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.

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.

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

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.

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.

well they would definatley notice a change in flight

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

• Bryce

That may be correct

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.

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
This has been a public service announcement. We now take you back to your regularly scheduled posts.

Are you close enough to Australia that you will have to throw them upside down?

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.