Need help with Daughters physics homework...

[frank]

Need some help here quick, needs to be turned in in the morning...How do we find the magnitude of the magnetic force from a straight wire with a 12 amp current flowing thru it at a distance of .11 meters? Any help here would be greatly appreciated...Thanks

[Cliff_J]

Obviously you need to show your own work and make sure its in the appropriate unit to the text of your daughters class, but a quick google search turned this up:

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magcur.html#c3

[Janitor]

I believe the equation in Cliff's link is derived from the Biot-Savart law and considerations of cylindrical symmetry of a straight conductor.

[2Pac]

F = \frac {4\pi10^{-7}I} {2\pi d}

where
I=current
F=force
d=distance from wire

[2Pac]

in order to find the direction of the force you must apply your "right hand" rules. let me know if you need help.

[Chen]

As a sidenote, 4\pi 10^{-7} is the permeability of free space and is denoted by \mu _0. For more information:
http://en.wikipedia.org/wiki/Permeability