Is my solution correct? (Electromagnetism problem)

[loki4000]

Homework Statement

H1=10
H2=-10
B1=1.5
B2=-1.5

Homework Equations

(change)Uloop = (change)H2*B2 + (change)H1*B1

The Attempt at a Solution

=(H1-H2)(B2-B1)
=(10-(-10))(-1.5-1.5)
=-60 j/m^3

 

[rude man]

You're on the right track but you have computed the energy dissipated in 1 cycle (but with the wrong units). Now convert the energy per cycle to the time rate of energy dissipation.

 

[loki4000]

You're on the right track but you have computed the energy dissipated in 1 cycle (but with the wrong units). Now convert the energy per cycle to the time rate of energy dissipation.

So, it sould be something like ((H1-H2)(B2-B1))*f ?

Where did I go wrong with units?
Is it j/m^2 due to area (not volume)?

 

[rude man]

You're on the right track but you have computed the energy dissipated in 1 cycle (but with the wrong units). Now convert the energy per cycle to the time rate of energy dissipation.

So, it should be something like ((H1-H2)(B2-B1))*f ?

Yes. A lot like! :-)

Where did I go wrong with units?
Is it j/m^2 due to area (not volume)?

You didn't go wrong. I did. The per-cycle energy dissipation units are J m^-3 just as you said. Except the final answer is of course in J sec^-1m^-3.

 

[loki4000]

Yes. A lot like! :-)

You didn't go wrong. I did. The per-cycle energy dissipation units are J m^-3 just as you said. Except the final answer is of course in J sec^-1m^-3.

So, final answer sould be:
=((H1-H2)(B2-B1))*f
=-60 * 50
=-3000 j sec^-1 m^-3
Makes sense. Thanx for help :)

 

[rude man]

So, final answer sould be:
=((H1-H2)(B2-B1))*f
=-60 * 50
=-3000 j sec^-1 m^-3
Makes sense. Thanx for help :)

OK, except no minus sign. Energy is dissipated in heat.