Question

Here it is

Answer 1

http://screencast.com/t/xlYZjI1O

Use energy principle to discuss why the disc eventually comes to rest

@AravindG

Answer 2

This is because of eddy currents.

Answer 3

Every time the conductor cuts the magnetic fields, and emf is induced which tends to oppose the field producing it(Lenz's law). Hence eventually it comes to rest.

Answer 4

how about this, due to the motion of the disc, relative to the magnet, a change in flux is produced , which induces EMF in the disc. According to lenz law, the induced EMF flows in a direction such that it opposes the change producing it, which means the magnet has a opposing force to its relative motion that eventually makes it stop?

Answer 5

Yeah looks good.

Answer 6

This resistive force is actually utilized as magnetic brakes in high speed trains.

Answer 7

how does that work ? care to explan :/

Answer 8

google for a video .... MIT OCW electricty and magenetism Walter Lewin

Answer 9

http://en.wikipedia.org/wiki/Eddy_current_brake

Answer 10

i have downloaded the MIT OCW Classical mechanics, not the electricity and magnetism, well il see abt it :)

Answer 11

basically the eddy currents are created as a result of lenz law ?