Brass Pendulum and Lenz's Law

[CrusstyJugglers]

I know conservation of energy laws won't be broken in this experiment, but can somebody explain why? Some kind of electrical energy being generated?

[elrddm]

@CrusstyJugglers Eddy currents generate internal friction which convert energy into heat. The brass pendulum should have a measurable increase in temperature.

[vedantganeriwala]

hi! i tried a slightly different experiment.

i used a pendulum with an iron bob.

i measured the time period of the pendulum.

and then i used a bar magnet and allowed the pendulum to oscillate directly above the bar magnet. the oscillation was in the direction of north south of the bar magnet i.e. along the bar magnet. the mean position the same as the equatorial axis of the magnet. i found that the time period with the magnetic field decreases, pendulum oscillates faster. why does this happen?

[Dogslax3333]

I thought this was stopped by an Eddy Current? maybe I'm wrong

[phydotsi]

@Dogslax3333

No, you're right. Please have a look through the video description - I mention eddy currents there. The effect of Lenz's Law is reduced by the slits in the brass, as the eddy currents are not as free to flow; when the eddy currents are limited, the pendulum swings for longer.

[kfstevens2370]

cool demo! thanks