A ticking clock sounds loud when you put your ear close to it. But as you walk away, the ticking gets softer and softer---until you can't hear the clock at all. Why does the sound get softer? The...
What is sound?
> Sound comes from just about everywhere--- from friends talking, radios > playing, jet planes roaring overhead. Even your breathing makes a tiny > sound. > > None of these sounds seem very much...
Hear All About It
Hear All About It Hear All About It
What makes these things work?
When you call a friend on the telephone, your voice doesn't really travel through the wire. Your friend hears a copy of your voice---a copy made by electricity. Inside the mouthpiece of your...
Lemon power
You can put your own \"package" of chemicals together to make a battery. A tiny magnet---a compass needle---will show you when the electric current is flowing. Ask a grown-up to use the knife to...
Packages of electricity
A flashlight runs on electricity---but you don't have to plug it in. It carries its electric current in a \"package"---a battery. A battery is made of layers of chemicals inside a metal can. When...
Making electricity safe
A light bulb uses only a little electricity. But electric stoves, refrigerators, and frying pans use as much electricity as dozens of light bulbs. Can you use too much electricity? What happens if...
A pull from electricity
You can build your own electromagnet---and you can find ways to make your magnet stronger. This project will show you how. Ask a grown-up to use the knife to scrape about an inch (2.5 centimeters)...
An on-off magnet
Large electromagnets can lift heavy loads. This one picks up and stacks big blocks of crushed iron and steel in a junkyard. Electricity can make light and heat. It can also make a magnet---one that...
It’s hot!
When you use electricity to make toast, pop corn, iron clothes, or dry your hair, two things happen. Electricity makes a strong push in a wire---and the wire pushes back! Electricity makes the...
