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Two bodies of mass 1 kg and 3 kg have position vectors k ˆ j ˆ 2 i ˆ + + and k ˆ j ˆ 2 – i ˆ 3 – + respectively. The magnitude of position vector of centre of mass of this system will be similar to the magnitude of vector :

1. k ˆ j ˆ 2 – i ˆ +
2. k ˆ j ˆ 2 – i ˆ 3 – +
3. k ˆ 2 i ˆ 2 – +
4. k ˆ 2 j ˆ – i ˆ 2 – +

Correct answer: k ˆ j ˆ 2 – i ˆ +

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