If the electric field near a proton is 9.00 x 10^-3 N/C, what is the distance from the proton?

Answer 1

E = 9*10^9 Q/r^2
here
Q = 1.6*10^-19
so
9*10^-3 = 9*10^9 (1.6*10^-19)/r^2

r^2 = 1.6 * 10^-7 = 16 * 10^-8

r = 4*10^-4 meters

= .4 millimeters

Answer 2

thanks!

Answer 3

You are welcome.