A 7.0-μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.3 m.If the resulting force on the second charge is 6.9 N in the positive x-direction,what is the force on the charge at the origin?
A)6.9 N in the positive x-direction
B)6.9 N in the negative x-direction
C)0 N
D)not able to be determined until the second charge is known
E)6.9 N in the negative y-direction

Question

A 7.0-μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.3 m.If the resulting force on the second charge is 6.9 N in the positive x-direction,what is the force on the charge at the origin?​
A)6.9 N in the positive x-direction
B)6.9 N in the negative x-direction
C)0 N
D)not able to be determined until the second charge is known
E)​6.9 N in the negative y-direction

Quizplus · Accepted Answer

According to Newton's third law, for every action, there is an equal and opposite reaction. Therefore, if the second charge experiences a force of 6.9 N in the positive x-direction due to the first charge, the first charge must experience an equal force of 6.9 N in the opposite direction, which is the negative x-direction.

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