A point charge q = +40.0 µC moves from A to B separated by a distance d = 0.180 m in the pres- A B ence of an external electric field E of magnitude 275 N/C directed toward the right as in Figure P16.6. Find (a) the electric force exerted on the charge, (b) the work done by the electric force, (c) the change in the electric potential energy of the charge, and (d) the potential difference between A and B. Figure P16.6

Consider the four particles shown, with q1 = –40.0 µC, q2 = –20.0 µC, q3 = 15.0 µC, and q4 = –25 µC. The square has sides of length a = 25.0 cm. a) What is the change in the electric potential energy of the system of the four charges in the configuration shown in the figure if they were originally infinitely far away? b) Charges q3 and q4 are now moved to points A and B, respectively. What is the change in potential energy of the system after these charges are moved? c) What are the magnitude and direction of the electric field at the location of charge q4 due to the other three charges? d) What is the initial acceleration of the charge q4 due to the electric force exterted by the other three charges on q4 if m4 = 40.0 g? e) With what speed is charge q4 (with m4 = 40.0 g) moving when it is infinitely far away from the other charges?   I need help with specifically D and E. Thanks!

The electric field in a particular region of space is found to be uniform, with a magnitude of 500 N/C and parallel to the +y direction. (a) What is the change in electric potential energy of a charge q=2.1 μC if it is moved from (x, y) = (20 cm, 45 cm) to (5 cm, 30 cm)? ml (b) What is the change in electric potential energy if the charge is moved the same distance along the x axis? mj

A uniform electric field of 2.0×105 N/C is oriented in the negative x direction. How much work must be done to move an electron 3.0 m in the positive x direction, if it begins and ends at rest?