Electric force charges homework

[danish1991]

1. A student is performing an experiment with two identical small metal balls, A and B. Initially, Ball A contains 6.0-uC net charge with unknown sign and Ball B is neutral. The student brings them in contact and then separated them by 20cm. Both of the balls are remained isolated. Is the electric force between A and B attractive, repulsive or zero?
Please help!

 

[tiny-tim]

hi danish1991! welcome to pf!

what happens to the charge when the metal balls are in contact?

tell us what you think, and why, and then we'll comment! ​

 

[danish1991]

Okay, thanks for replying! Its either between repulsive or zero. It cannot be attractive since both charges aren't opposite. I know its repulsive as the correct answer but wouldn't it be zero since ball b is neutral charged and ball a is positive because for attractive both charges got to be opposite to each other, repulsive they got to be same since its positive and zero how would it be repulsive?

 

[danish1991]

hi danish1991! welcome to pf!

what happens to the charge when the metal balls are in contact?

tell us what you think, and why, and then we'll comment! ​

Okay, thanks for replying! Its either between repulsive or zero. It cannot be attractive since both charges aren't opposite. I know its repulsive as the correct answer but wouldn't it be zero since ball b is neutral charged and ball a is positive because for attractive both charges got to be opposite to each other, repulsive they got to be same since its positive and zero how would it be repulsive?

 

[tiny-tim]

hi danish1991!

(just got up :zzz:)

you haven't answered my question …

what happens to the charge when the metal balls are in contact?