Consider a positive charge Q1 of magnitude 5.5 µC fixed at the origin with another positive charge Q2 of magnitude 8.5 µC moving near it. Charge Q2 has a mass of 4 g. Where applicable, let the potential energy be zero when charges are very far apart from each other.
a. What is the potential energy of Q2 when it is 5 cm from Q1?
b. If Q2 is released from rest at 5 cm from Q1, how fast is it moving when it reaches 7 cm from Q1?