Exam-style question
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If the gravitational force between two masses is 20 N when they are 2 m apart, what will the force be if the distance is reduced to 1 m?.
- A.80 N
- B.40 N
- C.20 N
- D.10 N
Model answer
What a good answer should say
- 80 N
Explanation
Why this works
Using the inverse-square law, if the distance is halved, the gravitational force increases by a factor of 2^2 = 4. Therefore, 20 N * 4 = 80 N.
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