Answer:
The rod`s charge must be positive, because the gravity force is pointing downwards and the electrostatic force must be pointing upwards (in order to balance the gravity force)
The charge is q_2 = 1.667 times 10^(-7) C
Explanation:
F_e = F_g
where F_g = m g and F_e= (1/4 pi e_0)*(q_1*q_2)/d^2,
please see the file attached for more details.