# Nasty Physics Assignment

#### babycat

[SOLVED] Nasty Physics Assignment

I was given this question by my physics teacher

"You were shown a demonstration whereby two cylindrical slugs of
metal were allowed to free-fall down a hollow vertical tube made of
copper.
One of the slugs, a magnet, took significantly longer to fall through
the tube than the other.
Why?
(i) Describe what you saw and try and explain why the fall times were
(ii) Can you think of a possible application for this effect?
You may have to go to the library to find the answer.
Minimum length should be one A4 page.
A Clue: Eddy current."

Does anyone have any idea what eddy currents has got to do with the result of this experiment????

Thanks!!!!

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#### HallsofIvy

Homework Helper
Do you have any idea what "eddy currents" are? If not, you might use your time at the library to look the term up. By the way, that sentence in the instructions "Use the principles described in the lectures to help you." looks important to me.

#### babycat

I do know what eddy currents are, I have looked at my lecture notes but I am having difficulty finding the correlation between the theory and the practical. I am not expecting anyone to give me the answer, I merely need a starting point.

#### Eyesee

Originally posted by babycat
I do know what eddy currents are, I have looked at my lecture notes but I am having difficulty finding the correlation between the theory and the practical. I am not expecting anyone to give me the answer, I merely need a starting point.
Get two magnets, orient the north pole of each toward each other and
see what happens.

#### russ_watters

Mentor
How does an electromagnet work? An electric generator? An electric motor?
I do know what eddy currents are
So tell us and we'll help you apply that to the current problem... We'll give you a nudge in the right direction.

Last edited:

#### babycat

Thanks anyway but I managed to solve the problem myself

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