Can we make a magnet fall in slow-motion? Is copper magnetic? How do we make electricity?
All great questions…Let’s find out!
You will need:
A straight copper pipe (at least 100cm in length)
Small neodymium magnets *adult supervision required*
A stopwatch/egg timer *optional*
Try holding a magnet against the outside of the copper pipe and let go – it doesn’t stick! That’s because copper is not magnetic.
Now try holding the copper pipe upright and drop the magnet through the pipe – the magnet should take several seconds to appear at the bottom of the pipe.
You can try timing how long the magnet takes to fall to the floor inside the pipe and outside the pipe with a stopwatch or egg timer.
Longer or thicker copper pipe will slow the magnet down even more.
The science bit:
Inside everything, there are electrons. If these electrons are facing or moving in a certain way they produce electricity.
Copper is not usually magnetic, so when a magnet is brought close to the copper pipe nothing happens. But when a magnet is in motion (when it’s moving) inside the copper pipe the electrons in the magnet pull on the electrons in the copper pipe which creates a small bit of electricity! This electrical energy doesn’t come from nowhere – the magnet has to convert some of its momentum (kinetic/movement energy) into electrical energy, and that’s why the magnet slows down while it’s falling through the copper pipe.
We make most of our electricity using large magnets and copper!