What is the magnitude of the force of particles?

1. Jan 18, 2010

haengbon

1. The problem statement, all variables and given/known data

Two charged particles exert an electrostatic force of 10 N. What will be the magnitude of the force if q1 is three times q2 and the distance between particles is increased to five times the original distance?

2. Relevant equations

3. The attempt at a solution

2. Jan 18, 2010

tiny-tim

Hi haengbon!

Call the original distance x.

What equations do you know that might help?

3. Feb 8, 2010

haengbon

I honestly don't know any equations for it :(

4. Feb 8, 2010

chemisttree

Have you heard of Coulomb's Law? Good place to start.

5. Feb 13, 2010

haengbon

is it the F=k(q1q2)/r2?

so... k=9x10^9 and F=10...

that's all I understand from it :(

6. Feb 13, 2010

tiny-tim

Hi haengbon!

(try using the X2 and X2 tags just above the Reply box )
Yes, that's the force of one charged particle on the other at distance r.

So how much will the magnitude, F, of the force be if the distance between the same particles is increased to five times r?

7. Feb 14, 2010

haengbon

so...it'll be

F= K(Q1Q2)/r
10= 9x109(Q1Q2)/ r(5) ?

I really appreciate your guidance through the whole problem ^^

8. Feb 15, 2010

tiny-tim

Hi haengbon!

(just got up :zzz: …)
i] what happened to r2 ?

ii] you're not reading the question carefully …

what is 10?