Question

There are two particles with charges +Q and +q. The electric force applied to one of the charges is 10 N. Now, +Q is replaced by +4Q while the charge +q is invariant. In addition, the distance between these two charges is doubled. What is the electric force exerted to each particle?

Answer 1

Answer:

F = 10 N

Explanation:

• Assuming that we can treat to both particles as point charges, the magnitude of the force that one charge exerts on the other, must obey Coulomb's Law.
• The expression for this force, applied  to the charges +Q and +q, separated by a distance d, is as follows:

       $F_{0} = \frac{k*q*Q}{d^{2}}$

• If we replace +Q by +4Q, and d by 2*d, the new expression for the magnitude of the force is as follows:

       $F_{1} = \frac{k*q*4*Q}{(2*d)^{2} } = \frac{4}{4} *\frac{k*q*Q}{d^{2} } = F_{0} = 10 N$

• As it can be seen, the force will be as same as before making changes, so F= 10 N.