Question

Two point charge +3 mueC and +8 mueC repeal each other with a force of 40 N. If a charge of -5mueC is added to each of them . The force between them will be

Answer 1

Answer:

10 N.

Explanation:

According to Coloumb's law

F= KQq/r^2

r^2 =KQq/F

given,

F= 40 N

Q=+8 μC

q=+3 μC

hence ,

r^2 = K (8)(3)/40= 3K/5 ----------(1)

again ,

when -5 μC added with each of them

Q'= +8-5= +3 μC

q"=+3 -5 =-2 μC

then ,

F' =KQ'.q'/r^2

=K (3)(2)/r^2

put equation (1)

F' =6K/(3K/5)=10N

Therefore,

Force=10N