Pendulum Wave Demonstration

This is a substantial-scale demonstration of the interaction between period of time and pendulum size, making use of sixteen bowling balls hung from a wood body.

Right here are solutions to some typical issues:

** What am I looking at? How does this work? **
The size of time it usually takes a ball to swing again and forth 1 time to return to its starting up posture is dependent on the size of the pendulum, not the mass of the ball. A for a longer period pendulum will consider for a longer period to entire 1 cycle than a shorter pendulum. The lengths of the pendula in this demonstration are all distinctive and had been calculated so that in about two:forty, the balls all return to the same posture at the same time – in that two:forty, the longest pendulum (in entrance) will oscillate (or go again and forth) fifty occasions, the future will oscillate 51 occasions, and on to the very last of the sixteen pendula which will oscillate sixty five occasions. Try counting how several occasions the ball in entrance swings again and forth in the time it usually takes the balls to line up yet again, and then rely how several occasions the ball in again swings again and forth in the same time (though it truly is a great deal more durable to retain your eye on the ball in again!)

** Who created this? **
This was created by Jeff Goodman, who teaches at Appalachian State University in Boone, NC. Jeff has some far more information and facts and video clips about the making of this pendulum wave at last-bowling-ball-pendulum-article-i.html

** Why are they not best at the stop? **
This substantial body is developed from wood and is outdoors, which means it expands, contracts, and flexes. Because the posture of the body improvements, the cycle lengths are not properly aligned. Variable strength reduction owing to air friction and the striking of the pipe at the bottom (which generates the new music) also add to discrepancies. More than time, the insignificant discrepancies come to be far more pronounced.

** Can I get a duplicate of this online video to use in my classroom? **
You are encouraged to use this online video for academic uses! If you are sharing on-line, remember to link again to this online video. Get in touch with me if you want to use it in other strategies or if you will need a higher-good quality version. This online video is available underneath Artistic Commons license BY-SA:

** How can I make my own? Wherever can I find out far more? **
Right here are some hyperlinks to information and facts about the physics at the rear of this. I don’t have the options for it, but work by means of the information and facts at these hyperlinks and design your own – you are going to find out a lot about physics, math, and building!
– to be-like-magic-but-its-physics
– Harvard demo web page:
– AJP paper:

** Wherever is this? **
It was developed on private residence in the mountains of North Carolina (United States), in close proximity to Burnsville. It is not open to the community. However, Jeff Goodman and I recommend some areas in close proximity to this that work to make the magic of the organic entire world a aspect of everyday everyday living. The pleasure and surprise in our entire world that these areas foster is *exactly* what drives the development of incredible factors like this pendulum wave!
– For all the young ones in your everyday living, test out Camp Celo:
This is a farm-residence camp for young ones 7-12 (and more mature young ones can work there!). It’s a great area for young ones to knowledge the organic entire world with independence and pleasure. No electronic amusement, just the residence-developed range like this pendulum wave. If you don’t have young ones to send out there, make a donation to Good friends of Camp Celo ( to assistance send out a boy or girl to camp who in any other case wouldn’t be able to go. (I am on the Board of this all-volunteer nonprofit and this online video was taken at 1 of their activities.)
– Proper future door is the Arthur Morgan University (AMS):
AMS is a progressive boarding and day university for 7th, eighth, and 9th graders, found on a hundred acres of farm and wilderness. At AMS, students find out to query, appraise, believe creatively and work cooperatively.

***If you’ve examine this considerably, will you do me a favor?***
Go to this link and vote for JJ to be the 2014 American Hero Puppy:
JJ is a incredibly distinctive tiny canine who guards a incredibly distinctive tiny female named KK’s everyday living by performing a little something just as magical as what you see in this online video: JJ makes use of her nose to detect when KK is possessing a most likely everyday living-threatening response, ahead of any medical products can detect it. Her physicians believe JJ is so great that they invited her into surgical treatment at Duke Healthcare Middle very last December! You can find out far more at The contest finishes on 9/15 and you can vote each individual day. If you like KK’s & JJ’s web page, you get a day-to-day photo and reminder:

Post time: 11-27-2016