Shared publicly  - 
 
MATHEMATICS • GEOMETRY
———————————————————————

Which Figure is drawn by the top of this stick ?

———————————————————————
1403
966
Mojtaba Rabiei's profile photoarun gowda's profile photoAum Sky Exits's profile photoJesse Ma's profile photo
425 comments
 
nothing, it doesn't have anything to draw with. but i would guess an oval.
 
its elypse.................>>>>>>>>>>>>
the mechanism is called "ELLIPTICAL TRAMMEL"
 
this isnt a circle for sure. this is an ellipse
 
the radius changes with time. how can this be a circle?
 
Circle. Most likely an optical illusion.
Updatec
 
Magnetic-self
 
There is nothing on it to draw, no page either.. lol
 
Ellipse
شكل بيضاوي ^_^
ls t
 
i think it's a circle
Translate
Translate
 
circle as major nd minor axis are f same length
 
major axis is along the stick when it is downward parallal to the groove and minor axis along the stick when it is horizontal...parallal to that groove. +hitesh bhatt
 
circle<ellipse is a special case of circle>
 
Muy bueno!!! es una elipse!!!!
Translate
Am ir
 
great
Translate
 
Trammel of Archimedes - ellipse
 
more importantly, lol @ square
 
It is an ellipse. If it were a circle, it would have a static center point. The pivot of the arm (the part moving near vertically in the animation) that would draw is moving in the North/South direction, but is static in the East/West. There is no way this contraption could draw a circle. Here's more explanation: http://en.wikipedia.org/wiki/Trammel_of_Archimedes
 
i made one found it in a old Mechanix Illustrated from September 1961
they called it a RECIPROCATING WATCHAMAJINGER
 
as i remember from school, Circle is Ellipse too...
with focuses in...
 
now will sum1 tell me wat is it?
 
It is ellipse. You can write its equation explicitly. If the length of the stick is L and the side of the square is 2*a, than equation of the figure it draws is x^2/(L-a)^2+y^2/L^2=1. Vertical and horizontal movements are not symmetric
 
Kentucky do nothing! FTW. It draws an ellipse.
Erica M
 
An oval (ellipse)
 
No figure is being drawn by the top of that stick. Isn't it obvious?
 
An ellipse is the locus of all points of the plane whose distances to two fixed points add to the same constant.
Ed B
 
oval/ ellipse
 
None, there is no pencil attached to the arm!! But if there were I reckon Oval.
 
It is a circle, it looks like an ellipse because it is an isometric view.
Correction: It is an ellipse formed by an Archimides Trammel as noted by partha sarathi Sahoo
 
I first thought an oval just by following the tip but on second thoughts the two pivots seem equal which points to a circle?
 
circle, all sides of the square seem to be equal.
 
An eliptically circular triangle. Previously undiscovered in this universe but very common in all others. Or so they lead me to believe..........:-P
 
I actually used to have one of these. I called it a bullshit grinder!
 
I have one of these. We call it a "do-nothing".
Translate
 
ellipse if L and B are different , circle L=B
 
i get confuzed,,,, but i feel it s cross
 
Assuming the block the arm is sliding on is actually square and not an optical illusion then an Ellipse. The pointing arm is at its longest when the middle block slides from side to side.
 
oval....Bi very nice trick i like it
 
circle, the moving objects in the square move the same amount.
 
It is an Ellipse. If it were a circle, the stick would have to be connected to the moving shuttles at regular intervals (i.e.- the 1/3 and 2/3 point). That way, the motion of each shuttle would affect the stick evenly. However, because of the necessity of equal motion between the shuttles, the shuttles would become locked, and the stick would not be able to make a full circuit! As it stands, one shuttle exerts a much greater influence over the direction of the stick, and they cannot collide. This is an animation of the Trammel of Archipedes, which draws an Ellipse.
 
What stick?

must be a "somebody elses problem" perception filter on it...
alex n
 
Ну это вообще классика
Translate
 
I had a toy called a "does nothing" It was exactly this.
 
niceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Nadia
 
obviously an oval but it would be interestin to see the outline defined! math is so intriguing, its like a giant puzzle!!!!
i hope one day i will be able to do geometry too. a journey takes one step at a time. ^_^
Translate
 
wow, watch those flashbacks, dude!
 
has no one else understood this???????
figure as in number it's 0
 
ellipse, like a parabolic sort of a cam in a car?
 
altough the logic says a circle, it seems more an elipse.
 
Wow! I actually HAVE one of these made of wood!
Translate
 
Well technically an ellipse since we aren't given the length of the x and y axis. And since a circle is a special case of an ellipse where x=y then ellipse is the most correct answer.
Translate
 
ellipse - I remember my grandfather giving me this toy as a gift, but with the stipulation that I figure out what it was!
Translate
 
Makes you think it's an oval, but it's a circle.
 
Ellipse ... there is not static centre point
 
not a elispe or circle becase this was done on a computer and pixels are square so it is technicly imposibel to make a perfect circle on a computer and becase of the stop of movment of the 2 yellow boxes that control the movment of the stick becase of them stoping movement there will be a slight corner so its a very very small sections so it wouldnt be a circle or elipse in life now how many sides there are I have no clue becase im only 13 and i dont have that technology on this computer to slow down the animation to see how many there are.
 
I'm amazed at how many people think it's a circle. Seems it's true that not everyone has great 3D interpretation :P
 
and to add on to that i forgot to mention that becase of the slowing movement to the boxes the stick slows down like a racecar driver slows down to turn even though there is banking if the banking was steeper they might not need to slow down but then they might just slide right (or left :P) off
Translate
 
ellipse, with major axis diamater = semi-axis diamater + length of square of box.
Translate
 
Running track shape or "capsule shape" straight on the sides
 
Surely, its Ellipse ==>> whose plane is not parallel to the axis, base, or generatrix of the intersected cone
 
It's an ellipse, search for "Archimedes Trammel"
 
Oval... Notice the difference in the distance to the squared base. Farther on the top and bottom, closer on the sides.
 
It's a circle but the angle at which your looking at it makes you think it's an ellipse. If it were an ellipse, the shuttles would have to move different distances but as the distances are the same, the lines drawn is the same width in all directions. This is a textbook circle equation made into a physical representation. I'm just going to give an example using a made up radii.
x^2 + y^2 = 16
 
Its an ellipse, and (since a circle is an ellipse) I will go a step further and say it is not a circle. Think about how far the tip of the board is away from the center of the contraption. You will notice that the two bricks are on the same side of the contraption when the stick is vertical extending the sticks tip a full stick length away from the center, but when the stick is horizontal, the two bricks are on the opposite side of the contraption as the sticks tip, extending the tip only half of the sticks length away from the center.
 
+Zachary Newton - That would only be accurate if the stick was connected at equal points to the shuttles. It isn't, meaning that the shuttles affect the stick in different proportions. So, you have to multiply your x and y times the percentage they are attached to the stick for a proper equation. Also, if they were attached to the stick equally (i.e. the 1/3 and 2/3 point), the shuttles would collide in the center, as they would be moving equally. This is a Trammel of Archimedes, and draws an Ellipse.
Josh M
 
I said ellipse also but because of the pivot point moving up and down - the one attached to the end doesn't really affect it that I can see.
 
if it was actually drawing I would say an ellipse
 
draw |drô|
verb ( past drew |droō|; past part. drawn |drôn|) [ trans. ]
- produce (a picture or diagram) by making lines and marks.

I do not see any marks... lines or whatever

So i'm sorry to disappoint you all but this thing doesn't draw anything...
you have all been fooled once again
 
Not a circle, an ellipse. If the stick was rotating around a fixed point, it would draw a circle.
 
The other end of the stick is making a rectangle!
 
i guess everybody is guessing wild !!! :)
 
it is an ellipse made by ellipsograph
 
ellipsographs are the new black... everyone should have them
 
This is like the 3rd time I've seen this same gif and posed question in 'what's hot'....I feel like I'm in the movie groundhog's day.
 
I will see your circle and raise you an ellipse!
 
Circle (in addition to sine ans cosine)
 
I put stickies on the screen, and it is clearly drawing an oval (or an ellipse) however the line drawn on the screen is a different oval than the one that would be drawn if we looked at the machine from above. And if we were treated to a true sense of perspective, we would clearly be working with an oval and not an ellipse.
 
The square root of the isosceles image is equal to the triangle on a raccoons ass. But just encase, don't put you lips on it, my Daddy used to have one of these things.
 
Since a lot of people seem to be confused, and giving the wrong answer...
There are a couple of ways of thinking about this to confirm you have the correct answer.
First, notice that the end is a fixed distance from the middle pivot, and in the frame of reference of the middle pivot, the tip moves in a circle. But the middle pivot is actually moving up and down with the motion of the rotation. So it's a stretched circle - an ellipse.
Second, the tip is a fixed distance from the end pivot. When the tip is top-left, the other end is in the centre of the + (close as it can be); when the tip is bottom-left, the other end is as far away as it can be; etc. The constraint on the other pivot forces an ellipse (again).
If you're still confused, google "ellipsograph".
 
Circle if the base is square, Ellipse if the base is a rectangle.

EDIT: Totally take it back. The placement of the bar differs(by half the length of the square) depending on whether it's vertical or horizontal. It's an ellipse.
Translate
 
you know an eight. . . but just erase where the lines connected. . . a small piece of it now . . . and then reconnect them but make sure there is nothing in the middle, kind of like a circle that is bent in the middle... Peace
 
its a square with rounded corners
you have to think from a top down perspective
 
ELLIPSE! It is definitively an ellipse. If the length of the stick between two pivots is b, and if the total length of the stick is (b+c), then the tip of the stick will draw an ellipse with one axis being equal to c, and the other one to abs(c-b). This is easily provable and seems to be known under several names including "Trammel of Archimedes" etc. Observe that in the case c is very large or if c=b/2, the curve indeeds becomes a circle.
 
Everyone seems to think its an ellipse - which it approximately is. If you set this up with servo drives driving the blocks, then the acceleration of the drives through each traverse would affect the exact points plotted - it's a particular approximation of an ellipse if we assume that the blocks accelerate smoothly - sinusoidally. You could delberately ramp the accellation so that the speed accross most of the traverse was constant, and your ellipse would be more distorted. The shape drawn is voluptuously beautiful, but it is not a perfect conic section, therefore, not a perfect ellipse. Elegant machinery, indeed. At first I thought irt would trace a Rouloux polygon...disappointed when I realised it wouldn't.
 
it is not ellipse, nor oval or circle. An amateur is trying to learn animation! lol
 
Circle - the radius up and down/left and right is the same therefore its a circle.
Translate
 
I agree with Dave. Its an ellipse!!!
 
This confused meh and also amused meh ........... O.O
Add a comment...