Is this faggot right or wrong, /sci/? https://www.youtube.c

4 times

>>7766345
problem is incomplete. You have to define around what fixed axis you count the revolutions.

>>7766352
>around circle B
Reading must be hard

>>7766352
The axis will move around circle B at circle A's centre. It makes 4 turns.

>>7766359
>literally this
But I accidentally closed my browser before posting it :^(

>>7766345
[eqn]\frac{2 \pi r}{2 \pi \frac{1}{3} r} = \frac{1}{\frac{1}{3}} = 3[/eqn]

>>7766359
Nice meme

>>7766359
>The axis will move around circle B
Nowhere is this asserted, you dunce.

>>7766359
>believing some cardboard cutout trick
He just made B 4x larger than A to trick you

>>7766370
>>7766377
>>7766397
samefag

i-its just circumference of b / circumference of a right? so 2pi/6pi = 3

this is bait isnt it?

>>7766409
it's not just the circumferences that matter. Rolling along a curved surface will revolve the object more than on a flat surface.

>>7766405
go back to reddit

>>7766417
Ah shit nigga I see now, but still, if this was asked on a SAT you'd still just answer 3 since 4 isn't an option.

it will revolve 4 times
3 times you can imagine it sticking to circle b as it goes around
1 extra time because if you image circle b dissapears then the circle is still turning in space over the whole period it goes around

>>7766417
How are you defining revolve?
How are you defining roll?

"The point of contact on both the stationary coin and the rotating coin must move the same distance, half the circumference of the coin. For example, the point of contact has moved from its right side to its left side. Correspondingly, the point of contact on the rotating coin must move from its left side to its right side. This means the rotating coin has made one full rotation about its own center while its center has made one half revolution about the stationary coin."

https://en.wikipedia.org/wiki/Coin_rotation_paradox

>>7766355
that doesn't mean anything.
Is it around the center of circle B? Is it around the point of contact between A and B?

Thinking must be hard.

>>7766478
It's pretty obvious what these mean. Think about a car driving over a hill. If you mark the top of the wheel of the car then the number of times this mark is at the top of the wheel from the perspective of an observer outside of the car is the number of revolutions the wheel makes. Rolling is simply the action of the wheel's circumference moving as it contacts the hill.

B has three times the radius, meaning it has three times the circumference. Thus, it will have to roll 5 times.

>>7766478
How are you defining "defining"?

>>7766347
This nigga is correct.
>20 replies to a troll pic

>>7766345
Based on the answers given the correct interpretation is implied.
It's 3.

If you are "enlightened" it's 4. Ever since Monty hall plagued this board everyone likes to feel smart going with the special answer.

would the answer be three if the smaller circle rolled around the Inside?

Does it roll without slipping or does it slip? What is the coefficient of friction between the two? Is there a force applied or are these discs in space and only acted upon by the gravitational force between them?

>>7766690
No, it would two.

A circumference of a circle is defined by the formula d of pi, or 2 of radius of pi.
The quarter demonstration is deceptive in the sense that given the quarter is rotated around completely, the bottom point is extended outward as a spiral, the length of that curve is that of the circumference. A rotation is not a revolution.

If they both stayed stationary, it would be 3. Otherwise you are accounting for the rotation around circle B as well, making it 4 turns.

So in general, one rotation of circle A is the circumference of A, another rotation of circle A is 2/3's of of the circumference of Circle B, another rotation is the full circumference of circle B. When the bottom of point of circle A touches Circle B. The length of that given curve is twice that of the circumference of A, so the entire length of that those arcs around B would be 6.