Physics Need Help PLEASE
posted by Jake .
Two point charges are separated by 8 cm. The attractive force between them is 14 N. If the two charges attracting each other have equal magnitude, what is the magnitude of each charge?

Coulomb’s law
F = k•q1•q2/r^2 = k•q^2/r^2
q = r•sqrt(F/k) = 0.08•sqrt(14/9•10^9)= 3.16•10^6 C = 3.16 microC 
Thank you so much Elena that helped me out a lot!
I was wondering if you could also help me with another question.
A droplet of ink in an industrial inkjet printer carries a charge of 6 1013 C and is deflected onto paper by a force of 2.4 107 N. Find the strength of the electric field to produce this force. 
According to the definition electric field strength is E =F/q, therefore,
E = 2.4•10^7/6•10^13 = 4•10^5 V/m 
its looking for the N/C I got 4*10^21 but I'm not getting it correct

SORRY!
E = 2.4•10^7/6•10^13 = 4•10^+5 V/m 
okay great!!! Thank you again!!!!
you do a wonderful job!!!! 
Two point charges repel each other with a force of 100N.One of the charges is increased by 10o/o and other is requced by 10o/o.the new force of repulsion at the same distance would be..
a.99N
b.125N
c.250N
d.300N