How Do Currents in Adjacent Wires Affect Their Mutual Force?

[jena]

Hi,

My Question:

A rectangular loop of wire lies in the same plane as a straight wire, as show in Fig. 20-57. There is a current of 2.5A in both wires. Determine the magnitude and direction of the net force on the loop.

http://www.webassign.net/pse/p31-09.gif"

where the width is 10.cm and width of the box is 5.0 cm and distance from the rectangular loop and the straight wire is 3.0 cm.

My Work

F=((mu constant)(I)^2(length))/(2pi(distance))
F=((4pi x 10^-7 Tm/A)(2.5A)^2(.10m))/(2pi(.05m))
F=2.5 x 10^-6 N

but the answer in the back of the book gives F=2.6 x 10^6

What did I do wrong

Thank You

 

[quantumdude]

You need to calculate the force on each segment of the loop due to the long straight wire, and add them up. It looks to me like you only attempted to calculate the force on a single segment.

It also looks like you've plugged in the wrong distance (that's supposed to be the distance from the straight wire to the segment you are analyzing).

And this bit here is confusing:

where the width is 10.cm and width of the box is 5.0 cm and distance from the rectangular loop and the straight wire is 3.0 cm.

Which one is the "width"?

 

[jena]

Sorry,

http://www.webassign.net/pse/p31-09.gif"

width=5 cm
Length= 10 cm
height= 3 cm

I thought the width would be used for the distance, but I guess that's wrong. I tried plugging in number but with no results close to the textbook answer of 2.6 x 10^-6 N

I still don't know what I did wrong though

Please help and Thank You