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This Week's Experiment - Swing Time
Greetings from the Buffalo Museum of Science. I have been having a wonderful time this week. My newly rebuilt Tesla coil is producing larger sparks than ever and the crowds have been great. It has been lots of fun meeting so many members of the experiment list at my shows this spring. If you do get to come to one of the shows, be sure to say hi.
*******Note to people that are waiting for experiment books*******
My frantic schedule for the past few weeks, plus a bout with food poisoning and some printing delays have put me behind on getting these out. I will be mailing them out this coming week, along with an extra "bonus" for your patience.
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For this week's experiment, I thought we would look into something that none of us seem to have enough of. Time. This experiment will not give you any extra time, but it will let you use up some time in learning how to measure it, without a watch.
Imagine that you are out in the woods, or on a deserted island, or in a hotel room in Buffalo. You want to time how many seconds it takes for something to happen, but you do not have a clock. Could you make an accurate device which would let you count the seconds?
For this experiment, you will need:
a key
a piece of string about 40 inches long
Tie the key to one end of the string. Now measure 39 inches from the end of the key and tie a knot in the string at that point. If you do not have a yardstick on your desert island (or in your hotel room), you can do what I did and use a sheet of 8 1/2 x 11 paper. That is the standard size for typing paper. Twice its length and twice its width give the right length for your pendulum. (8.5 + 8.5 + 11 + 11 = 39)
Now, hold the string at the knot and let the key swing freely. Hold your hand very still, or tie the string to something. I used the floor lamp in the hotel room. Pull the key to one side and release it. It will swing back and forth. Each swing, from one side to the other will take one second. I timed my pendulum with the stopwatch on my laptop computer and found it to be very accurate. After three minutes, when the pendulum was barely moving, it was still accurate to the second with the stopwatch.
The length of the pendulum controls how long it takes for the key to swing back and forth. It does not matter how heavy the weight is or how far back you pull it. A brick and a key will each take one second per swing on a 39 inch long pendulum. What if you wanted to make a pendulum that would swing from side to side in half a second? How long a string would you need? Should it be longer or shorter? How much longer or shorter? Try it and see. I will tell you that the length will probably not be what you expect it to be.
After trying this experiment, you should now know why grandfather clocks are so tall. The pendulum on a grandfather clock is 39 inches long, swinging back and forth to keep track of the seconds.
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Upcoming On-the-road schedule
April 28-29 - School shows in Madison, Alabama
April 30 - Solar Energy Center, Cocoa, FL
May 1 - Nature hike at Guana Refuge, Ponte Vedra, FL
May 4 - Berryhill School, Milton, FL
May 5 - Science Day, Grace School, Ocala, FL
May 7 - Yulee School, Jacksonville, FL
May 9 - Astronomy Day, Museum of Science and History, Jacksonville, FL
May 11-15 - School shows for FP&L, Ft. Pierce and Stewart, FL
May 16 - Scout extravaganza - NAS, Jacksonville, FL
May 19 - On-line presentation of "Hands-on Science", in American Online's
Homefront Hall
June 11 - Green Cove Springs Library, Florida
June 15-20 - American Museum of Science and Energy, Oak Ridge, TN
June 22-26 - Electricity Camp, The Center at Ponte Vedra, FL
June 29-July 3 - Science Wizards Camp, The Center at Ponte Vedra, FL
July 6 - 10 - Crime Busters Camp, The Center at Ponte Vedra, FL
July 13-17 - Dinosaurs Camp, The Center at Ponte Vedra, FL
July 24-27 - Grout Museum, Waterloo, Iowa
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Each week I will e-mail you a new experiment that you can try yourself. I look for experiments that are unusual, safe, dramatic, cheap, and fun. Since this list includes teachers, parents, science buffs, and students, I will try to give you a wide variety of things to try.
Please forward this e-mail to anyone that you think might enjoy it. If you received this e-mail from someone else and would like to be on the list, just send me an e-mail at krampf@aol.com, asking to be added to the Experiment of the Week List. If you ever want off the list, just send me an e-mail requesting to be removed.
Check out our web site at:
http://members.aol.com/krampf/home.html
for information on:
Watt is Electricity, the million volt electric show
The Nuts and Bolts of Lightning
Burning Questions, the science of fire safety
Educational consulting
Educator workshops
From Robert Krampf's Science Education Company
4850 A1A South
St. Augustine, FL 32084
(904) 471-4578