Two similarly and equally charged spherical metal spheres A and B repel each other with a force of 10^-5 N. A third identical uncharged sphere C is touched to A and then B and finally placed at mid point between A and B. what is net electrical force on C
spa13:
Can't we use formula...F=1/4pieabC not multiply by q1q2 divided by r^2. Hope u r getting wat i am tryin' to say..
The force depends on both the product of the charges and the distance between them
Ohkay. Got it ! thanks :)
Answers
Answered by
5
When C is touched to A each have charge Q/2
When C is touched to b then each have charge (Q/2 + Q) /2 = 3 Q/4
Fcb = k Q^2 (3/4)^2 / (R/2)^2 = k Q^2 / R^2 * 9 / 4
Fac = k Q^2 (1/2 * 3/4) / (R/2)^2 = k Q^2 / R^2 * 3 /2
Fcb - Fac = k Q^2 / R^2 * (9/4 - 3/2) = k Q^2 / R^2 * 3/4
Since Fab (initial) was k Q^2 / R^2 = 10^-5 N
the net force on C is .75 * 10^-5 N
Similar questions