Answer:
Given,
The charges,
q₁=8 mC
q₂= 2 mC
The force exerted by the 8 mC charge on the 2 mC charge, F₂₁=80 N
Explanation:
From the coulomb's law, the force between the two charges is proportional to the product of the two charges and inversely proportional to the square of the distance between them.
The force exerted by one of the charges is equal in magnitude to the force exerted by the other charge.
Like forces repel each other and the unlike forces attract each other.
Thus the force exerted by the 2 mC charge on the 8 mC charge will be equal in magnitude to that exerted by the 8 mC charge on the 2 mC charge, but the direction will be opposite.
Thus the force exerted by 2 mC charge on 8 mC charge is -80 N. The negative sign indicates the direction of this force is in the opposite of the force F₂₁.