The same balloon which has a charge of 7.2 nC is brought close to another student's hair who's charge is unknown. The force experienced is 152 N and the distance between the balloon and

hair is 0.15 m. What is the charge on the student's hair (the second charge)?

Athin nonconducting rod with a uniform distribution of positive charge q is bent into a circle of radius r. the central perpendicular axis through the ring is a z-axis, with the origin at the center of the ring. a) what is the magnitude of the electric field due to the rod at z = 0? n/c (b) what is the magnitude of the electric field due to the rod at z = infinity? n/c (c) in terms of r, at what positive value of z is that magnitude maximum? r (d) if r = 4.00 cm and q = 9.00 µc, what is the maximum magnitude? n/c