Calculating Charge on Two Pith Balls Using Coulomb's Law | Homework Help

[Hannahj1]

Homework Statement

The charge on two pith balls can be calculated by knowing their masses and observing the angle of separation between the balls.
If both balls are equally charged and they are suspended by strings that are 1.0 m long, calculate that charge.

Homework Equations

F = k q Q / d^2

The Attempt at a Solution

fnet=kqQ/d^2
ma=kq^2/d^2 (both q's are the same)
Im a bit stuck here because i don't know how to find the acceleration. Thank you!

 

[TSny]

Im a bit stuck here because i don't know how to find the acceleration.

The balls remain at rest.

 

[fireflies]

Why acceleration?

Why don't you try equilibrium of forces?

 

[Chestermiller]

Have you drawn a free body diagram on either of the balls, or do you feel you have advanced beyond the point where you need to use FBDs?

Chet

 

[jtbell]

fnet=kqQ/d^2

This is not F_net, because the electric force is not the only one acting on each ball. Your first step should be to choose one ball (either one will work, so you can toss a coin or something), then identify all the forces that act on it and draw a free-body diagram for it as Chet asked for.