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Homework Statement
A charge of -12.0nC is placed on the y-axis at y = -15cm and a charge of +12.0 nC is placed on the y-axis at y = 15cm. Determine (a) the electric field of each charge separately at x = 20.0cm, and (b) the net electric field due to these charges at x = 20.0 cm. (c) What force would act on an electron when it passes through this point on the x-axis moving at 1.73E6 m/s?
Homework Equations
E=k|Q|/r2
F=qE
c2=sqrt(a2+b2)
The Attempt at a Solution
(a) E=k|Q|/r2 = [(8.99E9 Nm2/C2) |12E-9C|] / (0.25m)2 = 1726 N/C
So...
E (due to +12 nC) = (1726 N/C , 323 degrees)
E (due to -12 nC) = (1726 N/C , 217 degrees)
(b) ENET = 2*(1726 N/C)*cos(53 degrees) = 2077 N/C, 270 degrees
(c) my problem is this part
I am given v = 1.73E6 m/s but with F=qENET, velocity of the electron is irrelevant? or may be I'm wrong.
F=qENET=(1.60E-19 Nm2/C2)(2077 N/C , 270degrees)
According to the answer key, the direction of the Force is 90 degrees? Why? From my drawing attached, I'm seeing 270 degrees. What am I doing wrong?