Does the mere thought of bungee jumping make your palms sweat? How about DIY bungee jumping at home with your kids? Don't worry, there won't be any broken limbs involved...just broken shells. In place of your child, an egg will be doing all the jumping.
The nylon pantyhose you'll use for this experiment has a natural elasticity and works like a bungee cord; the force of the falling egg causes it to change its form, but the strength of the fabric pulls it back. As you measure and conduct test runs, you'll be working out the components of Newton's famous physics equation: force = mass × acceleration. But before you jump into this experiment, be warned: it may get a little messy.
What You Do:
- Choose a spot for the bungee jump. A tree branch outdoors is ideal, but a ladder also works. You want the egg to fall to within an inch of your child's face when she's lying on the ground looking up at it, but no closer.
- Use the ruler to measure the distance from the back of her head to the tip of her nose; add an “inch for safety” to this number.
- Before experimenting with the egg, have your child work out the weight of the egg for a test run. Ask her to hold the egg in one hand and add pennies to the other until it feels like the coins weigh the same as the egg.
- Add the “egg’s worth” of pennies to a leg of the pantyhose and tape the end of the other leg to the branch or ladder.
- Do the test run. Let the pantyhose full of coins fall and check its distance from the ground. It should stop above the ground at exactly the distance that you and your child calculated in step two. If it doesn't, adjust the height of the pantyhose by retying it to branch or ladder.
- Now for the real thing. Remove the pennies from the pantyhose and replace them with an egg. Call in your audience, have your child settle in her place on the ground, and after a suspenseful countdown, do the drop. Bombs away!
If you decide to perform this experiment indoors, remember to spread newspaper on the floor. Otherwise, any near misses will be a pain to clean up!
Adapted with permission from "The Book of Totally Irresponsible Science." Copyright 2008 by Sean Connolly. Used with permission of Workman Publishing Company, Inc., New York. All Rights Reserved.