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A block of mass m is kept on a platform which starts from rest with constant acceleration g/2 upward, as shown in figure. Work done by normal reaction on block in time is - m a = 2 g

1. 8 t mg 2 2
2. 8 t mg 3 2 2
3. – 8 t mg 2 2
4. 0

Correct answer: 8 t mg 3 2 2

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