- #1
theKeeblerElf
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Homework Statement
A wire along the x-axis carries current I in the negative x-direction through the magnetic field
[tex]\vec{}B[/tex] = B0*(x/L) [tex]\hat{}k[/tex] 0[tex]\leq[/tex]x[tex]\leq[/tex]L
= 0 elsewhere
Part a was to draw a graph of B versus x over the interval -L[tex]\leq[/tex]x[tex]\leq[/tex]L, which I did.
b. Find an expression for the net force F_{\rm net} on the wire. Express your answer in terms of the variables I, L, and B0
c. Find an expression for the net torque on the wire about the point x = 0.
Express your answer in terms of the variables I, L, and B0
Homework Equations
Fnet=I*L*B*sin[tex]\alpha[/tex]
[tex]\tau[/tex]net=I*L2*B*sin[tex]\alpha[/tex]
The Attempt at a Solution
I thought that because I is carried in the -[tex]\hat{}i[/tex] direction and B points in the [tex]\hat{}k[/tex] direction that [tex]\alpha[/tex]=90 degrees, meaning I would be multiplying by 1. However, for both parts, when I submit I*L*B0 and I*L2*B0, respectively, the website says "Your answer either contains an incorrect numerical multiplier or is missing one."
For part b I've tried submitting -I*L*B0 because actually calculating I[tex]\hat{}L[/tex] X [tex]\hat{}B[/tex] yields a negative answer, but that didn't work either.
I've also tried to use x in my answer, and the website says the correct answer doesn't depend on it.
Any help would be much appreciated!