The strength of an electric field at 5.0 cm from a point charge is 100.0 N/C. What is the magnitude of the source charge? Show work so I understand how to do it.

E=kQ/r^2
solve for Q, you have r, E

What do I do NOW? I am lost

1 answer

Well, you basically told me the answer.
E = k Q / r^2
so
Q = r^2 E / k
here
r = .05 meters so r^2 = 25 * 10*-4 m^2
E = 100 N/C
k = 9 * 10^9 N m^2/C^2