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adca14
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Homework Statement
Three charges, +2.5[tex]\mu[/tex]C, -4.8[tex]\mu[/tex]C & -6.3[tex]\mu[/tex]C
are located at (-0.20m, 0.15m), (0.50m, -0.35m) and (-0.42m, -0.32m) respectively. What is the electric field at the origin?
q1 = +2.5[tex]\mu[/tex]C
q2 = -4.8[tex]\mu[/tex]C
q3 = -6.3[tex]\mu[/tex]C
Homework Equations
a[tex]^{}2[/tex] + b[tex]^{}2[/tex] = c[tex]^{}2[/tex]
v[tex]_{}x[/tex] = magnitude [tex]\times[/tex]cos([tex]\theta[/tex])
v[tex]_{}y[/tex] = magnitude [tex]\times[/tex]sin([tex]\theta[/tex])
E = [tex]\frac{kq}{r^{}2}[/tex]
law of cosines
k= 9x10^9
The Attempt at a Solution
first i found the hypotenuse for the three charges.
q1 = .25m
q2 = .6103m
q3 = .5280m
then i used the formula for magnitude of an electric field
where k is the constant, q was my three charges, and the radius were my three hypotenuses
my results were:
q1 = 360000
q2 = 115983
q3 = 203383
i used the law of cosines to get [tex]\theta[/tex]
my three angles were:
1 = 36.8
2 = 35
3 = 37.3
to find Ex, i multiplied the product of my magnitudes by the cosine of its respective angle:
my results:
1 = 288263
2 = 95007
3 = 161785
i added these up and got 545055, the book says 2.2x10^5!
i didnt bother doing y, since I am completely lost!
Please help me!