This rocket boosts a ball bearing using magnetic forces!
Safety: This activity involves a projectile ball bearing; never aim it at anybody and always have an adult present when operating.
You will need
a small rare-earth magnet (these very strong magnets can be found at hardware stores)
4 steel ball bearings
2 wooden skewers
card cut into a rectangle 10 cm x 30 cm
Blue –Tac or equivalent
What to do
Place the two skewers parallel (side by side) running lengthways down the card to form a rail. Leave a gap in between them large enough for a steel ball bearing to roll easily down its length. Use Blue Tac to secure them in place.
Place the rare-earth magnet a third of the way down the rail, sitting upright in the skewers. You will now have short and a long ‘runways' extending away from the magnet's face.
Line three ball bearings up, touching each other with the last against the magnet, pointing towards the long runway.
Gently roll the last ball bearing down the short runway towards the magnet.
What's happening?
The steel bearing is pulled by the magnetic field of the magnet, accelerating rapidly. It hits the magnet and this energy is transferred along the three ball bearings through collisions, into the third ball bearing in the line, which shoots off down the long runway.
All atoms possess something called an electromagnetic force. It is the force that atoms use to hold onto each another. If not for electromagnetic forces, nothing would stay together and all of the atoms in your body would drift apart, and the floor beneath you would not be solid enough to walk on. Electromagnetic forces of atoms attract or repel each other as they collide.
The ball bearings in the magnetic rocket are made of steel, which is a mix of iron and carbon. As the ball bearing rolls down the rail, the atoms of iron are pulled by the magnet's field, making the ball roll faster. Colliding with the magnet, it passes the kinetic (movement) energy through the line of ball bearings. The last ball bearing cannot pass it on, so it uses the energy to roll away.
Applications
This rocket is sometimes called a Gaussian ‘rifle'. Carl Friedrich Gauss was a German scientist who lived in the first half of the nineteenth century. He was a remarkable mathematician and something of a whiz-kid, making many of his discoveries when he was still a teenager.
One of his teachers attempted to occupy his class with a maths problem, asking them to work out what sum the numbers 1 to 100 made when all added together. He imagined it would take them a while. Gauss noticed that when 1 was added to 100, it made 101. And 2 added to 99 made…101. He went on, noticing that when 3 is added to 98, it also makes 101, and adding 4 to 97, and so on…all the way up to 50 plus 51, all giving the answer 101. To make the job easier, he thought of adding up 50 sums of 101, making in total 5050.
Gauss made numerous discoveries in mathematics, and worked with many scientists in fields of electricity and magnetism, studying the Earth's magnetic field as well as co-inventing the world's first electromagnetic telegraph in 1833 with a physics professor by the name of Wilhelm Weber.
How to set up your magnetic rocket.
You can have a cannon with two magnets to increase the thrust. This is how you would set it up, and ...
...watch it go! Be very carefull of where you point your rocket at this stage.