Electrostatic fields in vacuum

[smerep]

Homework Statement

An atom H has a charge +q (=proton) and -q(=electron). q = 1,6.10^-19.
The electron is circeling around the proton at r distance r = 0,53.10^-10m.

What is the force as a result of the electrostatic interaction between the proton and electron

Homework Equations

The Attempt at a Solution

F = (1/(4 x pi x epsilon 0)) x ((q1.q2) / r^2)

1/(4 x pi x epsilon 0 = 9 x 10^9 = k
q1 = 1,6.10^-19
q2 = -1,6.10^-19
r = 0,53.10^-10m

F = k . q.-q/ r^2 = k. -q^2/r^2
F = (9 x 10^9* 1,6.10^-19* -1,6.10^-19) / 0,53.10^-10*0,53.10^-10
F = -2,3 .10^-28/2,8.10^21 = - 8,2.10^-8

Is this correct?

 

[ap123]

Looks fine to me.

You don't need a minus sign for the charge, since you're working out the magnitude of the force.