- #1
TW Cantor
- 54
- 1
Homework Statement
An electric charge e which moves through a material of permeability μ with a velocity v, produces a magnetic field β at a point r given by:
β= ((μ*e)/(4*∏))*((v*ru)/(|r|)2)
where ru is a unit vector in the direction of r.
Find β if v=4i+3j+3k and r=4i+7j+5k.
Take μ=e=93 in appropriate units.
Homework Equations
equation for a unit vector: (a*b)=(a2*b3-a3*b2)i-(a1*b3-a3*b1)j-(a1*b2-a2*b1)k
The Attempt at a Solution
so i know μ .and e are both = 93 so i know that:
(μ*e)/(4*∏) is going to be a constant. i worked it out to be 688.266
i worked out |r|2:
42+72+52=90
then i tried to use the equation for a unit vector to calculate ru. this gave me:
ru = -48.902i + 0.060j - 65.143k
i then put all these values back into the original equation and it came out with:
β = -373.973i + 0.459j - 498.174k
when the actual answer is:
β = -4.836i - 6.448j + 12.897k
can anyone help me find what i have done wrong?