A point charge Q is located a short distance from a point charge 3Q,and no other charges are present.If the electrical force on Q is F,what is the electrical force on 3Q?
A) F/3
B) F/
C) F
D) F
E) 3F

Question

A point charge Q is located a short distance from a point charge 3Q,and no other charges are present.If the electrical force on Q is F,what is the electrical force on 3Q?
A) F/3 
B) F/ 
C) F 
D) F 
E) 3F

Quizplus · Accepted Answer

The electrical force between two point charges is given by Coulomb's law: F = (kQq)/r^2, where k is the Coulomb constant, Q and q are the magnitudes of the charges, and r is the distance between them. In this case, the force on Q due to 3Q is F, so the force on 3Q due to Q must also be F, because the forces are equal in magnitude but opposite in direction, by Newton's third law. Thus, the correct answer is C, F.

A Point Charge Q Is Located a Short Distance from a Point