Nova Physics Question

[ModelOD]

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Hey guys, I was wondering if you could help me on this Nova electrophysics problem. I keep getting answer that's a magnitude of 10 away from the actual answer and I want to find out where I'm doing my math incorrectly.

Question: Two charges, a positive charge Q=1.1*10^-10 C and a negative charge of the same magnitiude, are located 2*10^-6 m apart. A third charge q=10^-17 C is located exactly between them. What is the magnitude of the force on charge q?

I keep getting 2*10^-4 as the answer, but it says the answer is 2*10^-5.

The way I did the problem. I found the force on q of one of the charges and multiplied that by 2 in order to get the overall force on q.

kQq/r^2----> (9*10^9)(1.1*10^-10)(10^-17)/(10^-6)^2

I simplify the answer to the following: 10^-16/10^-12 and that's where I get 10^-4, which I multiply by 2 in order to get the final answer.

Does anyone know where I may be going wrong?

Thanks in advance for all your help!

 

[ModelOD]

Nevermind. I'm an idiot. I found out where I went wrong. Thanks anyways.

 

[cheesier]

This part:

(9*10^9)(1.1*10^-10)(10^-17) you can approximate as 10^10 * 10^-10 * 10^-17 which simplifies to 10^-17.

The bottom simplifies to 10^-12, and from there it simplifies to 10^-5 which you multiply by two. I would guess that your error was simplifying 9*10^9 to 10^9 instead of 10^10, but it is closer to 10^10.