SWINGING SCIENCE BY A SWINGING GAL

 



Swinging Science!

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Introduction

When I was very young I used to love going to the park on a sunny day and asking my parents for a push on the swing and naturally they would get tired of pushing me and I would persist of asking them for more and more pushes. When I became older either though experimenting and I don’t mean the science stuff experimenting it was probably what you would call trial and error or maybe by watching other older kids. I learned how to make the swing move without a push and also leaned how to pump it. I just took it for granted that eventually I could do this. I didn’t need dad or mom anymore I became “swing independent”. Now that I am fourteen and I know some what about science, experiments and controls I am curious as to what methods that I used to get the swing going worked. I am also wondering if there are any other swing like situations in real life that work like this or if any other use can be put from doing a science like explanation of this, if it can it would be really great so from the help of my dad and my curiosity this is what my project is on.

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Purpose

The purpose of my experiment is

  1. To investigate the effects of squatting and standing on a swing (during swing cycles) on amplitude.
  2. To initiate swinging motion without obtaining a push.
  3. To relate such swinging effects to real life situations and possibly to create a model that will simulate this.

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Apparatus

  1. Me.
  2. Playground swings (vinyl seat, chain see photos)
  3. Metric measure, various masses to add to the weight in my experiment (see photos)
  4. Pendulum model (see photo) simulation of periodic motion

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Method

A series of six experiments were done.

Experiment #1

  1. Starting to swing from a still position, swing was still in its mid position.
  2. I stood up and held the chains and pushed as shown on the photos and diagrams (see observations) starting motion or swinging.
  3. Once started, alternate sitting down (at the maximum points of the swing) and standing up (at the mid position) was started. Measurements were done recording the gain in amplitude for each cycle of swing.

Experiment #2

The process of step number three above was reversed with me sitting at the mid position and standing a the maximum point of the swing cycle gains in amplitude were recorded.

Experiment #3

Distance gained by standing all the time while swinging.

Experiment #4

Distance gained by squatting all the time while swinging.

Experiment #5

Starting from still position, trying to make the swing move.

  1. Stand up while at the still position. Pull on swing chains. Then push on chains and see if you start moving. If you do, then increase your distance by the squat, stand,squat positions as in experiment # 1.
  2. Starting from still position trying to make the swing move by squatting then pushing and pulling in sequence on the chains.

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Observations







Observation #1

Gain in amplitude by alternating sitting down, standing up, sitting down motions (as in photos) during the swing cycle.





Observation #2

Diatance gained by standing, squatting, standing motions.

Observation #3

Distance gained while standing throughout entire swing.

Observation #4

Distance gained by squatting thrughout entire swing.

Observation #5.1

Making the swing move from a still position while standing by alternately pushing and pulling on that chains while extending the feet.

CLICK HERE TO VIEW A SHORT VIDEO CLIP OF THIS MOTION.

Observation #5.2

Making the swing move from a still position while squatting by alternately pushing and pulling on that chains while extending the feet.

CLICK HERE TO VIEW A SHORT VIDEO CLIP OF THIS MOTION.

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Analysis

In a way the project was hard but also fun and exciting. I’ll start by answering my first question: why does squatting-sitting-squatting build the swing’s amplitude? It has to do mostly with energy and what you do to increase this energy. As energy is energy it does mostly two things: It can change one kind to another and it can transfer from place to place. I will be talking about two forms of energy. Potential energy depends on how far, rather how high, your balance is from some place (we call it ground level). The second kind of energy involved here is called kinetic energy. Depending what you do on the swing, potential energy changes to kinetic energy and you gain distance on the swing (amplitude).

So now imagine starting at some distance away from your still swing position. If you are squatting at this far end and then you stand up as you pass through your still position ( see my pictures entitled “still position” in experiment #1) then you squat again at the other for end, something happens to the types of energy. You start off with potential energy at the squat position, then as you move to your middle swing or still position, this energy is transformed in to kinetic energy and your speed increases. When you reach the middle (still) position, your whole energy is kinetic – you are moving at full speed. As you head towards the other end of the swing the opposite happens and you slow down. Now why do you gain distance or amplitude as you start off with a squat then stand (in the middle) then squat at the end again? As you stand up in the middle you raise your center of balance you transfer more potential energy to kinetic and this moves you further…sort of like a push. My graph # 1 shows this. If you reverse this stand-squat-stand you still gain a bit of distance but not very much. I cannot totally explain this. It may have something to do with smaller potential energy to kinetic energy changes. My graphs # 3 and #4 (where I either stand all through the swing or sit all through the swing) do not really seem to increase my distance, which kind of makes sense since there is not much change from one energy to the other.

Now for the other question. Pumping by squatting and then standing makes the swings go further and higher, but the new question is: How can I get the swing started from the still spot without receiving a push? And why does this work? I’ll explain what I did first to get it going from a still spot: While standing on the swing at the “still” position, I suddenly lean back and pull very hard on the swing’s chains to start moving in a swing fashion. I observed in the pictures we took that when I pulled on the chains my feet were forward, so some forces were pushing me towards my feet’s direction…forwards. Then when I stand on the swing I push on the ropes and this pushed my feet back and the swing rocks back. This starts the swinging and works whether I stand or sit. I remember doing this when I was small, but never really thought about how and why it works, I just did it. Now I know how and why it really works. So once you start your swing like this then you can do your squat moves and boom…you’re moving!

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Applications

  1. I now understand how and why my swing starts without a push and how it gets more distance once it moves. It would be very fun if teachers were to explain forces and kinds of energy by letting their students go to a playground and play and talk about science there.

  2. There is a place in Spain with a huge 700 year old church called the Cathedral of Santiago de Compostella. In the church is a huge container-like object that burns incense during special church holidays. They call this a censer. I went to the web and checked out the place. They have some real-time web cams showing the inside and outside of the church. The censor weighs as much as an adult male and hangs by a rope attached to a pulley from the ceiling (about 20 meters high). The other end of the rope hangs loose on the floor of the church. A number of men do something to make the censor swing in a way like the swings in my experiment. The censor is first pushed to start it swinging. Then the men pump the censor by squatting, standing, squatting…sort of…instead of squatting and standing they do this: As the censor passes through its still point they pull hard to shorten the length of the censor and rope swing by about 3 meters. When the censor reaches the high point of the swing they relax their pull and this makes the length of the censor and rope increase to where it was. This is like my pumping: squat, stand, squat. These men’s moves change potential energy to kinetic and increase the energy by doing this. As this swings, the coals burn the incense and spread the smell through the church. It is said that in the old days people from all over Europe and Asia came to visit this church. Because they got very dirty when they traveled, they smelled bad. The censor covered the smell and made them feel close to God at the same time.

    The photograph to the right shows the Botafumeiro Censer of the Cathedral of Santiago de Compostela, Santiago de Compostela, Spain. The picture was obtained from http://www.dickinson.edu/~nogierm/Pictures.html.

  3. Possibly, the way space shuttles re-enter the earth’s atmosphere could be fixed to work like a swing and reduce the energy the shuttle has instead of increasing it (the opposite of my project).

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Conclusion

  1. Squatting, standing, squatting increases your swing distance.
  2. You start swinging from “ standing position” by doing the push-pull method on the chains.
  3. Some cool applications come out of this.

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Acknowledgements

  • Thanks to my dad for all his help trying to make me understand something I used to do when I was a kid. Now I understand why I did this, but it is not as much fun knowing why it happens.
  • Thanks to my sister for helping to set up my web page.

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