Electromagnets are incredibly strong magnets often used for industrial or military applications to move heavy objects or shoot light ones ridiculously fast. However, YouTuber Physics Girl teamed up with Joe Hanson to demonstrate the power that lies behind an electromagnet.
ArcAttack, the group that assisted in making the video possible is a popular science performance group who chooses to play with electricity rather than traditional instruments. The team is familiar with high voltages to create the resonance necessary to create music out of ‘thin air’.
The team is also responsible for engineering a device that can obliterate a can in a fraction of a second. Using intense magnetic fields amplified by a current which create a secondary current within the can. Both expel a magnetic field facing the same poles, resulting in an extreme force that tries to separate the fields as quickly as possible. However, since the can lays directly in the center, it instantly explodes under the tensional forces.
Using another apparatus set up with an intense magnetic field, the team was also able to shrink a coin to half its original size. The experiment works by wrapping a coil of wire snugly around the quarter. A capacitor is then charged with an incredibly high voltage which is quickly released through the wire. The coil induces an intense magnetic field which then induces a current on the coin. The changing magnetic field also induces an intense force directed inwards. In the coins instance, the charges moving at the edge experience the inward force. The intense current (many times over the lethal dose for a human) was so incredibly powerful that the quarter then pulled itself inward, resulting in the shrinkage.
The experiment is a great example demonstrating the forces and components required to make an electromagnet.
[Image Source: Physics Girl]