Rem magnetik
Trains and rollercoasters increasingly stop using magnets rather than friction pads. This simulation shows a conducting sheet moving past a magnet, the eddy currents induced in it, and the retarding force that results — with nothing physically touching the moving part.
Cara memakai simulasi ini
- Set the initial speed of the conductor
- Change the field strength and the conductivity of the sheet
- Compare with a non-conducting sheet
Yang perlu diamati
- The braking force is largest at high speed and tapers off as the object slows
- Nothing makes contact, so there is no wear and no friction dust
- Kinetic energy ends up as heat in the conductor rather than in brake pads
Fisika di baliknya
Motion through a non-uniform field changes the flux through parts of the conductor, inducing eddy currents. Lenz's law dictates that these oppose the motion, so a drag force appears. Crucially the force is roughly proportional to speed, so braking is strong at high speed and fades as the object slows — the brake decelerates smoothly but never quite stops the object on its own.