Question 1
In the figure, if
Q = 30
μC,
q = 5.0
μC, and
d = 30 cm, what is the magnitude of the electrostatic force on
q?

◦
15 N
◦
23 N
◦
zero
◦
7.5 N
◦
38 N
Question 2
Rubber rods charged by rubbing with cat fur repel each other. Glass rods charged by rubbing with silk repel each other. A rubber rod and a glass rod charged respectively as above attract each other. A possible explanation is that
◦
Any two rubber rods charged this way have opposite charges on them.
◦
Any two glass rods charged this way have opposite charges on them.
◦
A rubber rod and a glass rod charged this way have opposite charges on them.
◦
All rubber rods always have an excess of positive charge on them.
◦
All glass rods always have an excess of negative charge on them.