Electric Forces with particles and Columbs law problem.

[Toon]

Homework Statement

Two particles, one with charge -7.13 × 10-6 C and one with charge 1.87 × 10-6 C, are 0.0284 meters apart. What is the magnitude of the force that one particle exerts on the other?
Two new particles, which have identical positive charge q3, are placed the same 0.0284 meters apart, and the force between them is measured to be the same as that between the original particles. What is q3?

Homework Equations

Fe=Kq1*q2 /r^2

The Attempt at a Solution

So for the first part. I got the answer right for the force which was 148.7 N. However for the second part, I tried doing Fe= kq3^2/r^2 and solved for q3. However I keep getting 3.6 x 10 ^-6 columbs and that's wrong according the my physics homework website. Any help where I am going wrong?THanks!

 

[TSny]

Could it be that you are not expressing your answer to the correct number of significant figures?

 

[Toon]

Could it be that you are not expressing your answer to the correct number of significant figures?

thats what I am thinking. However I've tried diffrent ways of expressing the answer and its still wrong so I am assuming my numbers might be off.

 

[TSny]

What do you get to 3 significant figures?

 

[Toon]

What do you get to 3 significant figures?

3.651 x 10 ^-6 but the answer is still wrong

 

[TSny]

Well, your answer certainly looks correct to me.