Question

Q1
Two point charges +3
MICROC and +8 microC repel
each other with a force of 40N.
IF a charge of -5 micro C is
added to each of them, then the
force between them will
become​

Answer 1

according to inverse square law we know that

F= Kq1 q2/r^2

first we have to find r square

r squared value is given in the above picture

now adding minus 5 microcoulomb to each charge we get

+3-5= -2

+8+-5=3

now we have to find the force between the two charges

the answer is given above in the second picture

force between the two new charges is 10 Newton