Slow-mo tunnel

The faster it falls, the slower it goes!

Difficulty:
Danger:
Duration:
5 minutes

Safety

  • Carefully review the general safety advice on the back of the box cover before starting the experiment.
  • Read the "Magnets and electricity" section of the safety guidelines carefully before proceeding. Do not let children under 8 years old handle small magnets.
  • Disassemble the setup after the experiment.

Disposal

Dispose of solid waste together with household garbage.

Scientific description

As you already know, magnets don’t just interact with other magnets—they also attract ferromagnetic materials . Magnets have an invisible area around them where their force extends, which is called their magnetic field . When one magnet is brought into the magnetic field of another, they begin to interact, attracting  or repelling  each other. The farther magnets are from one another, the weaker their interaction.

In this case, the fall of your magnet is slowed by the influence of a different magnetic field . So where does it come from? The tube  is not attracting the magnet; it is not made of ferromagnetic material and cannot form a magnetic field. In fact, a magnetic field is created in the non-ferromagnetic tube due to the movement of the magnet  itself! As its magnetic field  moves with it through the tube , the moving magnet  initiates the directed movement of electrons —tiny charged particles that exist in everything.

The circular movement of electrons  inside the tube creates a magnetic field  directed opposite to the magnetic orientation of the falling magnet. These magnetic fields repel one another, and the magnet’s  fall is slowed. And the more the magnet accelerates, the stronger the magnetic field of the tube becomes, which slows it back down.