Two point charges of +2 microcoulombs and +3 microcoulombs are 0.3 m apart. Using k = 9 x 10^9 N m^2/C^2, what is the magnitude of the force between them?
Answer and explanation
Correct answer: A. 0.6 N
- Step 1: F = kq1q2 / r^2. Step 2. F = (9e9)(2e-6)(3e-6) / (0.3)^2 = 0.6 N. Answer: 0.6 N. Why not the others: 0.18 N: this multiplies by the distance instead of dividing by its square. 0.05 N: this multiplies by the distance squared. 6 N: this makes an error of a factor of ten in the powers of ten.
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