(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Two long parallel wires, each with a mass per unit length of 40g/m, are supported in a horizontal plane by 6 cm long strings, as shown in the figure below. Each wire carries the same current I, causing the wires to repel each other so that the angle (theta) between the supporting strings is 16 degrees.

a) Are the currents in the same or opposite direction?

b) Determine the magnitude of each current

Figure:

2. Relevant equations

[tex]\Sigma F=ma[/tex]

[tex]B= \frac{\mu_{0}I}{2\pi r}}[/tex]

[tex] F_{b}=BIl[/tex]

3. The attempt at a solution

For a) I know that the current must be in the opposite direction.

For b)I drew a Free Body Diagram first and found that [tex] T_{x}=F_{B} [tex] and these are the same for both wires.

However, how do you find the tension if they don't specify the exact weight of each wire? They do tell you that each of the wires have "a mass per unit length of 40g/m" but how do you convert that to weight if you don't know how long the wires are? Thanks!

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# Homework Help: Hard Magnetism Problem

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