Two point charges exert a force F on each other. One charge is multiplied by 3, the other by 3, and the separation is multiplied by 3. What is the new force?
Answer and explanation
Correct answer: C. 1 F
- Step 1: Coulomb's law: F is proportional to q1 q2 / r squared.
- Step 2: New force = 3 x 3 / 3 squared x F = 1 F.
Answer
1 F.
Why not the others: 3 F, 81 F and 0.667 F do not fit.
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