Goal Use the superposition principle to calculate the electricfield due to two point charges.
Problem Charge q1 = 7.00 µC is at the origin, and charge q2 = -5.35µC is on the x-axis, 0.300 m from the origin (Fig. 15.12).
(a) Find the magnitude and direction of the electric field at pointP, which has coordinates (0, 0.400) m.
(b) Find the force on a charge of 2.00 10-8 C placed at P.
(a) Calculate the electric field at P.
Find the magnitude of 1 with Equation 15.6.
E1 = 3.93 105 N/C
Vector 1 is vertical, making an angle of 90° with respect to thepositive x-axis. Use this fact to find its components. E1x = E1cos(90°) = 0
E1y = E1 sin(90°) = 3.93 105 N/C
Next, find the magnitude of 2, again with Equation 15.6.
E2 = 1.92 105 N/C
Obtain the x-component of 2, using the triangle in Figure 15.12 tofind cos ?.
E2x = E2 cos ? = (1.92 105 N/C)(0.600)
E2x = 1.15 105 N/C
Obtain the y-component in the same way, but a minus sign has to beprovided for sin ? because this component is directeddownward.
E2y = E2 sin ? = (1.92 105 N/C)(0.800)
E2y = -1.54 105 N/C
Sum the x-components to get the x-component of the resultantvector. Ex = E1x2x = 0 + 1.15 105 N/C
Ex = 1 N/C
+ E
Sum the y-components to get the y-component of the resultantvector. Ey = E1y2y = 3.93 105 N/C - 1.54 105 N/C
Ey = 2 N/C
+ E
Use the Pythagorean theorem to find the magnitude of the resultantvector.
E = 3 N/C
The inverse tangent function yields the direction of the resultantvector.
? = 4°
(b) Find the force on a charge of 2.00 10-8 C placed at P.
Calculate the magnitude of the force (the direction is the same asthat of because the charge is positive). F = Eq = E(2.00 10-8C)
F = 5 N
(a) Place a charge of -3.60 µC at point P and find the magnitudeand direction of the electric field at the location of q2.
E = N/C
? = ° counterclockwise from the positive x-axis
(b) Find the magnitude and direction of the force on q2.
F = N
? = ° counterclockwise from the positive x-axis
I Don't know how to do this Please help Me. Thank you. The top partis how i figured out the rest i think its the missing informationto solve the bottom part.