Centrifugal Force?

[Libby]

Alriiight. So, most people know that I have a comic, (although almost dead from my lack of intrest) and I have had an issue with working with the basic idea of the comic. I know this idea is fairly cliche, but it's kinda cool when joined in the aspect of the comic. Which I won't reveal, 'cause I'm a pain in the butt.

Imagine you are in an amphitheatre. A huge circular one, with a center stage. The big problem is, is that it is spinning. Each of the rows represents a "time period." My issue is, what row is spinning the "fastest?" Meaning, would the center rows be feeling a faster spin then then the outside because it's moving at less distance, or would the outside rows be moving faster?

I'm not too sure how to explain this, but I feel it's one way, and I've had an argument brought up how it could be another. A good way could be looking at the planets, but I'm still not sure.

So, beyond dead center, is it faster on the outside of the merry-go-round or the inside?

[Valkysas]

Re: Centrifugal Force?

inside. closer to the inside you are, the less you're traveling on a circular path, and the more you're just spinning around.

[Wavelength]

Re: Centrifugal Force?

I really don't know for sure. I don't think the figure skater analogy would work here (shrink your own radius to increase angular momentum), since the revolutions per minute will be the same for all points on the carousel/centrifuge. My guess is that each "era", or each person inside the centrifuge, would "feel" it the same because they're making the same amount of rpm.

[IRC]

Re: Centrifugal Force?

Or water down a drain.

[Sejon]

Re: Centrifugal Force?

The orbits of planets don't necessarily work as a great analogy because the planets farther from the primary must perforce be revolving more slowly since they're not as deep in the system's gravity well. So the ones closer are always moving faster, even if they're covering significantly less distance in their semi-major axes.

I'd say the circumferential row is moving the fastest because it's covering the most distance.

To illustrate, simply spin around at a somewhat consistent speed with your arm bent towards your chest, and then hit the wall with your fist. Probably won't hurt. But try it again, spinning at the same speed, with your arm outstretched, and that hand is going to hit the wall with more force. That's because it's now going faster and carrying more momentum.

[IRC]

Re: Centrifugal Force?

just like water down a drain.

[Wavelength]

Re: Centrifugal Force?

I'd say the circumferential row is moving the fastest because it's covering the most distance.

To illustrate, simply spin around at a somewhat consistent speed with your arm bent towards your chest, and then hit the wall with your fist. Probably won't hurt. But try it again, spinning at the same speed, with your arm outstretched, and that hand is going to hit the wall with more force. That's because it's now going faster and carrying more momentum.

The outside is without doubt experiencing the most total movement--but this isn't about movement, it's about "feeling" a force. They might be absolutely related for all I know, though?

[IRC]

Re: Centrifugal Force?

Well if you look at it from feeling a force then I would think it was the outside. The rotation of the room would cause everything to be thrown to the outwards away from the center. Think back to the merry-go-round of days yonder. Was it more fun to stand in the middle or to hang on for dear life from the outside rails?

[Kojiro v. 2.1.14r7b]

Re: Centrifugal Force?

Depends on what form of speed you are referring to really. If it is spinning speed, if anyone has ever been on a Merry-go-round at the playground and sat in the center, it appears to spin faster. However this could be construed as false since it only appears to be spinning faster, so it is a relative speed. Similar to when you are driving items farther away appear to move by slower because of parallax.

Now, let's think on distance per time. The outer most row revolves in the same amount of time as the rest of the amphitheater, however it has a longer circumfrence. Therefore, it can be decided as moving faster because speed is generally referred to in units of distance per units of time, I.E. Miles per Hour.

There was a very similar question on a physics test I took once. Right next to "It's pouring rain outside, would you get more wet running or walking to the door from your car?"

Edit: spinning objects are rated in RPM, and the entire thing is making the same RPM, just something to think of.

[Zieg Rauros]

Re: Centrifugal Force?

I think, if you take a straight line from the center, and measure one rotation, the outside moves much farther at the same RATE therefore, more SPEED.

[Wavelength]

Re: Centrifugal Force?

There was a very similar question on a physics test I took once. Right next to "It's pouring rain outside, would you get more wet running or walking to the door from your car?"

That must have been an interesting physics test. It's walking, right?--you mighr run "through" less rain per second, but you give yourself a much longer time to have it dump down on you from above.

[thetruecoolness]

Re: Centrifugal Force?

Well they are all spinning at the same absolute speed (well angular speed), however the outside is spinning faster linearly speaking because they are making the same revolutions per minute as the other guys but are traveling a greater distance. I think this is one of the main reasons that data on the outside of a hard disk drive is read at a faster rate than inside. Though I guess whether you are, or you feel you are going faster are sometimes two different things depending on frame of reference.

That's my take anyway, it's been a while since I took Physics.

[Kojiro v. 2.1.14r7b]

Re: Centrifugal Force?

That must have been an interesting physics test. It's walking, right?--you mighr run "through" less rain per second, but you give yourself a much longer time to have it dump down on you from above.

I think the answer ended up being neither because you hit as many rain drops running as walking, ont op of that, there is a point of saturation where you don't get "more wet" anymore. As fast as drops are hitting you they are running off of you. Something like that.

[The Toecutter]

Re: Centrifugal Force?

I believe you are looking for centripetal force, not centrifugal.

a * R = v^2


a = acceleration
R = radius
v = velocity


For a given speed at which the ampitheatre is spinning, the closer you are to the center, the greater your angular acceleration. This is where the greatest force will be experienced.

While the perimeter will be spinning a greater distance per unit of time at a given speed than the center, an object at the center will have the most force.


Depends on how you define 'feeling', because while the outside will be faster in an absolute velocity sense, the inside is what will 'feel' faster since that is where greater amounts of force are experienced.

Further, a disk spinning at a certain rpm is spinning at that rpm as your point of reference approaches the center just the same as it approaches the perimeter.

[truekid]

Re: Centrifugal Force?

outer edge, sez i.