# Coulombs law question

## Homework Statement

What is the magnitude of the force a +12 µC charge exerts on a +2.7 mC charge 43 cm away?

## Homework Equations

I know I have to use the equation: F=kq1q2/r^2

## The Attempt at a Solution

F=(9*10^9)(12)(2.7)/(43^2)
=157706868.6

???right???

## The Attempt at a Solution

F=(9*10^9)(12)(2.7)/(43^2)
=157706868.6
???right???

almost, attention to the unit system you are using....

so i would change mC to C and cm to m...
F=(9*10^9)(2.7*10^-6)(12*10^-6)/(.43^2)
=1.58 N

is this ok?

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