Best Demo of the Tennis Racket Theorem (Dzhanibekov Effect)
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- čas přidán 22. 04. 2013
- A demonstration of how tennis rackets, cereal boxes, and toys spin differently depending on their orientation. This is a direct application of the intermediate axis theorem. You can see many demonstrations of how objects tumble in space.
Each axis of rotation has a different moment of inertia. This causes rotation to tumble around the axis with the intermediate moment. A classic demonstration of the Tennis Racket Theorem also known as the Dzhanibekov Effect.
Your videos are so cool! It makes me feel like a kid marveled by all these science facts of the daily life that are not even taught at most engineering schools.
Also the way you film in first person, gives a wonderful immersion.
The tippy top flips because of friction with the table that produce a torque which in turn flips the top. However, the tennis racket and cereal box do not need that friction - rotation of it is unstable around the intermediate axis, even when you spin in space where there is no gravity. Tippy top needs the gravity to have the friction with the table. Two effects are not the same.
This is one of those things that I’ve always known about but never knew what it was. Today is the day I find out. Thanks CZcams.
I was watching reviews of wireless home cinemas... and now I'm here. Dammit CZcams!!
I wonder if the reason the apple doesn’t work is relative to its size it has fairly little mass, so maybe the momentum is lower relative to the screwdriver.
MORE VIDEOS please.
CZcams algorithm you do it again!
Search for 'Dzhanibekov Effect' and all your questions will be answered
No, it will rotate properly if you find the correct axis. The axis simply changes depends on the orientation. A proper axis will make it stable. What throws it off is friction due to imperfections in the object. The proper axis of the tennis racket it a couple inches from the top (the end furthest from the handle)
John Martin is not correct...the tennis racket will always spin/tumble if flipped about its axis with intermediate moment of inertia...it is not a matter of shifting the rotation axis up or down a bit. It will spin stably if spun about either of the other axes, however. Also, the effect causing the top to flip over and for the tennis racket to flip (when spun about its intermediate moment axis) is not the same. The top flips due to a torque caused by the point of contact.
Formally, I think he was right, a PURE rotation about the axis with intermediate moment of inertia is an equillibrium point of the torque-free
rigid body euler equations, thus a PURE rotation (i.e. with angular velocity only about the intermediate axis) will mantain there in time. But is an unstable equillibrium point, so even the slightest deviation from that intermediate axis rotation will make it tumble and flip about its axis. Yes, practically it is impossible to make our body rotate with zero angular velocity on the other axis that are not the intermediate one, but mathematically what he said wasn't wrong.
@@victorpicon2616 Beat me to it 🙂
RE: 1:20-- 2:06. SEE the Veritasium video "The Bizarre Behavior of Rotating Bodies" @9:55--.10:18.
kinda funny to be talking about a physics example (the theorem) but then having problems realizing a different physics problem trying to make an apple and screwdriver do the theorem
now I want apple. sigh
Put your drill on that applestick
The earth is doing this right now. The North Pole and South Pole are swapping as we speak The North Pole has been moving south at a rate of 5 mile per month for the last 20 years and is now in Siberia
Crazy complicated math you say? Oh trust me i can explain it to cats for couple minutes
told you
sugar is bad for you
Yep Yep Yep Dumb Dumb Dumb
*GET A JOB!*
Sha Na Na NA (aint going back to rehab)
Sorry but the best demo is with a cat