Four point charges have the same magnitude of 2.4 X10 -12 C and are fixed to the

Question

Four point charges have the same magnitude of 2.4 X10-12 C and are fixed to the corners of a square that is4.0 cm on a side. Three of the charges are positive and oneis negative. Determine the magnitude of the net electricfield that exists at the center of the square. The answer is 54 N/C. I need to know how tofigure. Four point charges have the same magnitude of 2.4 X10-12 C and are fixed to the corners of a square that is4.0 cm on a side. Three of the charges are positive and oneis negative. Determine the magnitude of the net electricfield that exists at the center of the square. The answer is 54 N/C. I need to know how tofigure.

Explanation / Answer

E = -qk/r^2
Just convert all distances into x and y components and solve for Exand Ey separately. Then use Ex^2 +Ey^2 = E^2

So, for example in the x direction, we have:
Ex = -qk/x^2 Be sure to account for direction (i.e. if the charge is to the leftof the point in question, you multiply by an additional negativevalue to represent the direction vector being negative.)

we would then get:

Ex= -k( -q1/x1^2 - q2/x2^2 +q3/x3^2 +q4/x4^2):       Notice that because two ofthe charges (in my arbitrary example, that's q1 and q2) are to theleft of center, there are negatives in front of them accounting forthe direction vector. (Also, in your case x1^2 will be equalto x2^2,x3^2 and x4^2

To find the direction, just use arctan(Ey/Ex) =

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.