- #1

Mutaja

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## Homework Statement

You're given two bar magnets as shown below. In the gap between the two bar magnets, there's a bit of copper that's 1mm thick. The area of the bar magnet is 2.5cm

^{2}, and the flux density is 0.5T. Compute the force between the two bar magnets.

## Homework Equations

## The Attempt at a Solution

So the force is given by this formula:

F = B

_{∂}* H

_{∂}* A

_{∂}

H

_{∂}= [itex]\frac{B

_{∂}}{µ

_{0}}[/itex] = [itex]\frac{0.5T}{4∏ * 10^-7}[/itex] = 397887

F = 0.5T * 397887 * ##2.5cm^2## = 497385.

The answer I get is about 20 000 times bigger than what I'm expecting.

Where am I going wrong?

F is the force.

B is the flux density in the air gap.

H is the field strength in the air gap.

A is the area in the air gap.

I'm sorry for the use of the wrong symbol, but ∂ was the closest I could get.

Also, I realized that I have a gap filled with copper instead of air, just as I was about to post this. I have no examples involving gaps with anything else than air as far as I'm aware. I will keep looking for this and update this post if I find anything.

Any input is appreciated.