1. (2 pts) A charge of -7C is fixed at the origin. A charge of +3C is moved from a position 5cm away from the charge to one 8cm away from the charge.

a. Defining the electrical potential energy as zero if infinitely far away from a charge, what are the initial, final, and change in electrical potential energy of the charge? Remember to include a plus or minus sign as appropriate.

b. How much work is done by the electric force (not the force being used to move the charge!) in this process? Remember to include a plus or minus sign as appropriate.

2. (2 pts) A conducting plate held at 0V lies in the y-z plane at x=0. A second plate held at +100V lies in the y-z Plane at x = 1cm. A particle with mass 5 x10^-7kg charged with -3C is released at rest from close to the 0V plate and travels to the 100V plate.

a. What is the electric field (magnitude and direction) between the plates?

b. What force (magnitude and direction!) does this field exert on the charge?

c. Using force and distance, determine the work done by the electrical force when the charge moves from one plate to the other. Remember to include a plus or minus sign as appropriate.

d. What are the initial, final, and change in electrical potential energy of the charge? Remember to include a plus or minus sign as appropriate.

e. Using the result of (d) find the amount of work done by the electric force in this process. Remember to include a plus or minus sign as appropriate.

f. If no other forces were acting on the charge, what is its velocity when it reaches the positive plate?