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A pulse of light of duration 100 ns is absorbed completely by a small object initially at rest. Power of the pulse is 30 mW and the speed of light is 3 × 10 8 ms –1 . The final momentum of object is

1. 0.3 × 10 –17 kg ms –1
2. 1.0 × 10 –17 kg ms –1
3. 3.0 × 10 –17 kg ms –1
4. 9.0 × 10 –17 kg ms –1

Correct answer: 1.0 × 10 –17 kg ms –1

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