Four particles are positioned on the rim of a circle. The charges ...

[notis]

Four particles are positioned on the rim of a circle. The charges on the particles are +0.500 C, +1.50 C, -1.00 C, and -0.500 C. If the electric potential at the center of the circle due to the +0.500 C charge alone is 4.50  104 V, what is the total electric potential at the center due to the four charges?
  1.18.0  104 V
  2.4.50  104 V
  3.0
  4.-4.50  104 V
  5.9.00  104 V

Question 2

At what distance must the object be placed on the principle axes in front of a concave mirror for the image to appear the same size as the object? Draw a ray diagram to illustrate your answer.

[coyin]

Answer to Question 1

2

Answer to Question 2

The object must be placed at the radius of curvature.