It’s getting nice outside. Time to start thinking about backyard science! Here’s one of our favorites, if you haven’t already tried it! W
“Kids aren’t getting dirty these days. They’re not playing in the mud, not playing in rain puddles,” says Dr. Truglio, of Sesame Workshop in a Wall Street Journal article, about getting your kids outside.
Next to the kitchen table, my back yard (or front yard) is my favorite science laboratory. It has the added bonus of being easy to clean up. For this fun, messy experiment, a hose and a few paper towels do the trick. Make your kids clean up whatever mess they make!
My dad, who is a physicist, told me about this great demonstration. It teaches kids a little bit about motion and force while letting them do something that they are rarely, if ever, allowed to do- throw eggs! All you need is a sheet, some clothespins or string, raw eggs, and some paper. (You could use newspaper or easel paper. It is just to make cleaning up easier.) I also used a portable table turned on its side as a wall, but you could just use a wall or the side of a garage and have your child hose it off when you are finished.
Hang the sheet up from a tree, if you have one. If you don’t have a tree, you could hang it from anything else, or have two tall children or adults hold it. Then have two kids hold the bottom of the sheet up, or tie it to chairs so it makes a J shape when you view it from the side. The idea is to keep the eggs from hitting the ground and breaking.
An object in motion wants to remain in motion. To stop an egg moving through the air, you have to apply force to the egg. In this case, the force will be applied by a hanging sheet, or a wall.
Throw a raw egg at the sheet as hard as you can. It won’t break because the sheet slows the movement of the egg as it comes to a stop. The law of motion says that the faster you change the speed of an object, the greater the force applied to the object will be. When you change the speed of the egg slowly, like the sheet does, it lessens the force applied to the egg and the egg remains intact.
Now, put some paper on a wall (or table like we did.) Throw an egg at the wall. You’ll see what happens when something stops fast. Once again, the law of motion rules. When you change the speed of the egg quickly, it stops with a lot of force. SPLAT. This is my kids’ favorite part.
This is why they put airbags in cars. If a car is moving and hits something, causing it to stop very quickly, the airbag act like the sheet, slowing the person in the car down SLOWLY and greatly reducing the amount of force they might hit the dashboard with.
Record your results in your science notebook, if you want to. Finally, be sure to wash your hands when you’re finished experimenting and cleaning up. Raw eggs can have bacteria called Salmonella living in them and on them. Have fun!