physics coulombs law
posted by adithya .
a negative charge 5.0 X 10^-4 C exerts a repulstio force of 7.0 N .on second charge away 0.05 m away.
what is the sign and magnitude of the second charge
find the force exerted by proton and the electron in a hydrogen atom they are 5.0 X 10^-19 coulomb