A 1.50 g object with unknown net charge is moving towards a -2.8 µC source charge. When it is 0.80m from the source charge, it has a speed of 22 m/s. When it is 0.40 m from the source charge, it has a speed of 12.5 m/s. Use ke = 9.0x109 N·m /C .
a) What is the charge on the 1.5 g object?
b) What is the closest distance the 1.5 g object will get to the source charge? (Hint: At this closest distance, the object is stopped momentarily while changing direction. What is the speed of the object at this moment?)