Transform your next park visit into a science experiment by playing with the physics of swings. Pendulums are simply weights suspended by strings that move back and forth with the assistance of gravity. So, whenever you sit on a swing and move back and forth, you’re a human pendulum!
For this experiment, you’ll need a swing set with two or more swings.
How to Do This Experiment
Step 1: Have your child sit on a swing with their legs straight out. Tell them to keep their legs still, or it won’t work.
Step 2: Pull them up and back as far as you can. Ask your child whether they think the swing will hit you if you let go and it swings back.
Step 3: Let go of the swing without pushing it. Remain standing straight in the same spot. Does it hit you on the return swing? If you followed the directions, it shouldn’t! Let your child try it with someone smaller than they are.
Step 4: Try swinging side by side with your child at exactly the same rate on swings that have chains of the same length. Once you’re synchronized, stop pumping your legs. Do you stay together? Does it matter who is bigger and weighs more, or do you stay together?
Step 5: Try the same thing with swings that have chains of different lengths. Now what happens? Who swings faster?
The Science Behind the Fun
Playground swings are pendulums, and the shorter a pendulum’s string, the faster it swings!
But a pendulum never swings back past the point at which it was released, unless you add energy, like a push. That’s why, when you pull someone back on a swing and simply let go, they won’t hit you on the return swing, unless they add energy by pumping their legs.
You can find more experiments like this one at kitchenpantryscientist.com, and in my books Kitchen Science Lab for Kids (Quarry Books) and Outdoor Science Lab for Kids (Quarry Books).
© Quarry Books, 2016/Outdoor Science Lab for Kids
Featured Photos Credit: © Quarry Books
