PreQuiz 1617.2 .:. Go Up
Vector Fields
Each grid line is a meter. Charge A is +12.4 x 10^{6} C, and charge B is 36.1 x 10^{6} C. Find the electric field at the origin. Draw the vector as an arrow with its tail on the origin, and label the angle you calculated. Carry at least 4 sig figs for your calculations.
Fill this in:

magnitude 
trig. angle (opt) 
x 
y 
E_{A} 
=Kg/r^{2} =(8.99E9)(12.3E6) /√(5^{2}+4^{2}) =2718.93 
=270+tan^{1}(5/4) =321.34 (Since A is positive, the E field is away from it) 
=Mag(cosӨ) =2718.93(cos 321.34) =2123.13 
=Mag(sinӨ) =2718.93(sin 321.34) = 1698.5 
E_{B} 
=Kg/r^{2} =(8.99E9)(36.1E6) /√(4^{2}+3^{2}) = 12981.56

=tan^{1}(3/4) =36.87 (Since B is negative, the E field is toward it) 
=Mag(cosӨ) =12981.56(cos 36.87) =10385.23 
=Mag(sinӨ) =12981.56(sin 36.87) =7788.94 


E_{A} + E_{B} 
12508.37 
6090.45 



Magnitude 
Trig Angle 



=√(12508.37^{2}+6090.45^{2}) =13912.32 N/C 
=tan^{1}(12508.37/6090.45)) =25.96 degrees

Completed by Sarah Smurthwaite