What's the maximum angle a swing can obtain?

I spend a lot of time at the playground and watch and play on the swings a lot. It’s lead me to wonder what the maximum angle that a swing can obtain with only the swinger’s own power.

From my own experience and from watching the teenage kids it seems that one can get around 90 degrees and then the chains slacken and jump.

So what is the maximum angle a swing could obtain? Would chain length make a difference?

As bonus question what’s the world’s tallest swing set? I keep getting hits for highest.

On Mythbusters an acrobat took a swing with rigid arms instead of chains, standing on a platform instead of seated, and turned it 360 degrees. I don’t recall their analysis of a chain swing, seated, and pumping with the legs.

With a solid connection (not chains) you can 360.

http://www.youtube.com/watch?v=d3FrvV3It5U

How about if we limit it to chain/rope only since it’s been shown that poles can do 360.

Right. As is strongly suggested by the video, this is what prevents a self-powered swing with non-rigid arms from getting more than a small ways past horizontal.

However, theoretically, if one would pump hard enough, and move fast enough, wouldn’t that prevent the chains from slackening? It seem to me that there’s no reason why this should be categorically impossible, and that the only real reason is insufficient muscle strength.

You’d have to go from less then horizontal to a full 360 in one shot without building up to it. If you stop anywhere between that point the chains will go slack. With solid poles, you can keep ‘pumping’ and building up to a 360 even after your swinging past the horizontal. Also, you’ll notice, they usually just barely make it over the top, it’s not that they rocket all the way around in a circle. If you did that with chains, you’d fall on the bar.

Having said that, there’s no reason why you couldn’t go all the way around if you had the power. It’s no different then swinging something around on a chain or string.

Also, you would turn inside out.

Shit, I remember Inside Out Boy!

On Mythbusters, even with a bunch of big guys pulling, they couldn’t get a swing to go much higher than 90 degrees. And even then, you can only do that once, because then you fall and lose momentum. They had to use rockets to go 360.

Ah yes, rockets - they tend to resort to that option on rather small provocation.

You can’t get much above 90 degrees because the only thing powering you is gravity. All you do when you pump is move your center of gravity back and forth. If you want to go higher, you need additional power - a (very) stong push, or rockets, or something like that.

Having a daughter that likes to go to the park, I can confirm that chain slack will ruin every attempt… because I try all the time!

I can also discuss popping wheelies on a bike if anyone is interested.

Sometimes being a parent and role model is hard.

But what about standing on a swing. From a standing position you can do much more to change your center of gravity.

If you are willing to cheat a bit I think I have a way to do a loop even with a chain and gravity pumping. At each end of the swing arc, a bit less than 90 degrees either way, you have an array of magnets. And opposing magnets on the swing itself. This allows you to pump the system to a much higher speed than just gravity allows. Once you get the speed high enough you turn off the magnets and do a loop.

Yeah, in one way its cheating. But those magnets are NOT adding any energy into the system. They are just allowing you store more into it before you do a loop. Though you better have a system to deal with the N+1 loop that won’t quite make it and you fall out of the top of it.

Why is this different than for pumping on the rigid bar swings. There is an additional source of energy, it’s the muscle power.

This reminds me of one of my favorite things to do as a child.
Swing as high as you could and then at the top of the arc, jump.

This works best when the landing surface is not concrete, but back then (way back in the twentieth century) your typical playground was either hard packed dirt or concrete. None of this namby-pamby can’t-break-a-leg wood chips for us. We risked our lives on a daily basis and rarely did any of us actually die. Lacerations, contusions, fractures, concussions, and internal bleeding? Certainly, but that which didn’t make us stronger almost killed us. Wait… strike that. The other way. Yeah that’s it. We also drank from the garden hose when we were thirsty and that’s the way we liked it! Tell kids that these days and they will never believe you.

Harrumph!

Wait, was this about swings?

The chain going slack shouldn’t actually be an insurmountable problem, since it doesn’t actually remove any energy from the system. If anything, the loss in energy should come in the collision where the chain goes taut again. Come up with a way to store the energy dumped there, and it should be manageable.

Yes, but the problem is pumping energy into the system when slack (and something else I am too lazy to explain at the moment).

For a system with possible slack you need to pump enough energy into the system in one cycle to go to from being able to doing a ± 90 to doing a full 360. I’ve come up with way that doesn’t involve magnets but I’ll keep it a secret for now :slight_smile:

You don’t have to go all the way from low-angle to 360 in a single cycle, nor do you have to pump while slack. If you have some way of holding onto the energy, you could just continue to pump during the taut part. I think it might be doable if we replace the chains with an elastic material.