Answer:
-1.4N
Step-by-step explanation:
When the distance between A and B is 13.8mm (0.0138m), the force exerted by A on B is 2.65N:
F(A,B) = k*qA*qB/r²
=> 2.65 = k*qA*qB / 0.0138²
=> k*qA*qB = 2.65 * 0.0138²
k*qA*qB = 0.0005046
When the distance between them increases to 19mm (0.019m), the force exerted by A on B becomes:
F(A,B) = k*qA*qB / 0.019²
Given that k*qA*qB = 0.0005046,
F(A,B) = 0.0005046/0.019²
F(A,B) = 1.4N
The force exerted by B on A will be in the opposite direction of the force exerted by A on B, which means that the force exerted by B on A will be:
F(B, A) = -1.4N