Current Attempt in Progress

A two$-$stage rocket moves in space at a constant velocity of $+4670\frac{m}{s}.$ The two stages are then separated by a small explosive charge placed between them. Immediately after the explosion the velocity of the $1070-kg$ upper stage is $+5810\frac{m}{s}.$ What is the velocity $($magnitude and direction$)$ of the $2390-$kg lower stage immediately after the explosion?

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