Drop Supermagnet through aluminmum pipe (1 Viewer)

[krabby_me]

If you drop a marble through an aluminimum pipe, it falls straight down. If you drop a magnet down it, it falls much slower without touching the sides. It just sort of hovers down.
How can i explain this Phenomenon using both diagrams and text?

 

[jm1234567890]

eddy currents

 

[thunderdax]

This is an example of Lenz's Law. Induced eddy currents are caused by the change in flux over time in the sections of the pipe. I think there's a diagram of how it works in Macquarie textbook

 

[rama_v]

http://www.boredofstudies.org/community/showthread.php?t=63996

Similar question with diagram

 

[helper]

Lenz's law causes it to slow down

Don't say this in the HSC, it is the reason people lost marks a few years ago.

Say It is an example of lenz's law. Then talk about a changing magnetic flux, producing an induced current that will oppose the original change etc.

 

[thunderdax]

lol, yeah, sorry, i was really tired when i typed that up

 

[dawso]

depending on the question, u can also include a reference 2 the fact that it is an example of electro magnetic braking....