if my calculations are correct.....

the escalator would have to be moving at a pretty good clip...

2*pi*r*L where r is the radius of the coil and L is the number of stacked coils.

I'm sure it's close enough;) Calcualte how much extra lenght you'ld need of the offset were the width of the wire.

Originally posted by powermacG6
That is clearly wrong, because you havn't allowed for the fact that each coil is not planar. Try again.

Clearly there is also the issue that unless you are heating the coil it will never be straight...

Originally posted by Wrong Robot

Another thing I'd like to do is ride a wheeled something(bicycle, skateboard, scooter, unicycle) on one of those horizontal escalator dealies at airports.

Hmm. I want to do that too! Great idea.

Originally posted by Wrong Robot
Another thing I'd like to do is ride a wheeled something(bicycle, skateboard, scooter, unicycle) on one of those horizontal escalator dealies at airports.
The problem is you'd be tackled, beaten, arrested as a terrorist, thrown in jail, and give a full body cavity search while your bicycle was being x-rayed then sliced into tiny pieces in a search for explosives.

Not that there's anything particularly scary or threatening about a bicycle in an airport, but these guys just don't have much of a sense of humor anymore.

Originally posted by powermacG6
That is clearly wrong!;)

You havn't allowed for the fact that density is dependant on temperature:lol:

Trivial

L(T)=m/A(T)p(T)

QED

Originally posted by Scott
Trivial

L(T)=m/A(T)p(T)

QED

Heh. Assuming that the thermal expansion of the material is the same in all directions, A(T)= p(T) (V(T1)*A(T1)/m) where the V(T1) and A(T1) are the volume and cross sectional area of the slinky at a given temperature T1, respectively.

This gives:

L(T)= m^2/(p(T)^2 *(V(T1)*A(T1)))

Of course this is assuming that the added mass energy from heating is negligible -- which as we know is an invalid assumption when discussing an infinitely long slinky, which we clearly are...

Infinitely long? :?: We're trying to estimate the length of a manufactured slinky.

Why don't we come to a consensus on the level of error we're willing to accept and that will help guide us on how complex our model needs to be? I think if we were within a centimeter that would be good.

I'll contact the manufacture to see of we can get several hundred for destructive testing.

about 63 feet.

I would sit down with a hamburger and a soda and start unwinding the slinky during lunch, gamely trying to force straightness out of a hardened, flattened, coiled wire. I would get ketchup everywhere, I would knock over my drink by accident several times and I would cuss. Oh how I would cuss. It's likely that I would at some point cut myself, and very possible that I would throw it down and jump up and down on it, eventually.

Any measuring I might accomplish would be cursory and half-hearted, and I would surely forget the length by the time I arrived back at the Burger Doodle to buy the chocolate milkshake designed to calm my nerves and sooth my ass-kicking by a child's toy.

QED

ummmm, I haven't. What is it? (yes, I went there to look but couldn't figure it out). What IS it?