# Two identical conducting spheres,fixed in place ,attract each other with an electrostatic force of 0.108 N when their centre to centre separation is 50 cm . the spheres are then connected by a thin conducting wire.when the wire is removed ,the spheres repel each other with an electrostatic force of 0.0360 N .of the initial charges on the spheres,with a positive net charge,what was a)the negative charge on one of them and b)the positive charge on the other ?

Arun Kumar IIT Delhi
8 years ago
$\small F=kq^i_{1}q^i_{2}/r^2=0.108 \\F=kq^f_{1}q^f_{2}/r^2=0.036 \\q^i_{1}+q^i_{2}=q^f_{1}+q^f_{2}$
Where the superscript means initial and final.
Also Since connected by a wire
$\small \\(q^i_{1}+q^i_{2})/2=q^f_{1}=q^f_{2}$
We will get a quadratic equation now.
You can easily solve that.
Thanks & Regards
Arun Kumar
IIT Delhi