 Now we're ready to move to part C of this calculation. Calculate the magnitude of force between the two charges. Well in order to do that we want to use Coulomb's force law. Now that says the magnitude of the force is K, Q1 the first charge, Q2 the second charge over R squared. And we're only working with the magnitudes here. Well my K value is 8.99 times 10 to the ninth Newton meter squared per Coulomb squared. On my calculator it uses the exponent button instead of the times 10 to the button so your calculator might do that or it might do times 10 to the ninth. Then we have to put our two charges in. And notice the first charge is plus 2.4 micro Coulombs. So remember that when you put that in it's the 2.4 times 10 to the minus 6 because that's what the micro means, Coulombs. And our second one is the 1.5 micro Coulombs. And so again that's 1.5 times 10 to the minus 6 Coulomb. Now I went ahead and left the minus sign in here but because it's inside the absolute value sign on your calculator you're probably just going to want to put in the number. So rather than put in plus and minus we just put in the 2.4 and the 1.5 with the times 10 to the minus 6 for the micro Coulombs. And then for the R position you're going to put your 0.3 meters in for R and don't forget that that's squared. I'm going to give you a moment here to take your calculator plug that all in for yourself. Make sure you know how to put that in but then you should get a value of 0.3596 Newtons. Now you can round that off to 0.360 because it could be three significant digits or you can leave it all the way out. It does have units of Newtons because it's a force and at this point we don't have the directions in there at all.