4. In the figure below, q = 1.0 x 10-7 C and a = 5.0 cm, where V = 0 at infinity. a) What is the electric potential at the center of the square? b) What is the potential at the lower left corner due to the other three charges? c) How much work is required to set up the charge configuration in the figure, assuming the charges are initially infinitely far apart from one another? d) Give a brief physical interpretation of the sign of the work found in part c. +q -q a (+29) Answer: a) 0 V a α b)-31 kV a -29) c) -6.9 x 10-3 J

Imagine a parallel plate capacitor with mica between the plates.   Suppose the potential difference between the plates is 82V, and there is an electric field between the plates with a strength of 320 N/C.  If each plate has an area of 0.030 square meters,   a)  What is the separation between the plates? b)  Find the capacitance of the capacitor. c)  How much charge is on each plate? d)  How much energy is stored in the capacitor?   For each part, explain your reasoning.

In the following figure, a charge q1 = 4.0 × 10-7 C is located at y = 8.0 m. A second charge q2 = 3.0×10-7 C is located at x = 5.0 m. %3D a) Find the x and y components of the electric field at (0,0). b) Find the electric potential at (0,0) c) Find the x and y components of the force on a particle with a charge q3 = -2.0 × 10-7 C if it is placed at (0,0). у (m) 8 92 x (m)

A) Find the electric potential at point P in the figure B) Suppose the three charges shown in the figure are held in place. A fourth charge, with a charge of +5.32 μC and a mass of 5.23 g, is released from rest at point P. What is the speed of the fourth charge when it has moved infinitely far away from the other three charges?