A two-stage rocket moves in space at a constant velocity of 4800 m/s. The two stages are then separated by a small explosive charge placed between them. Immediately after the explosion the velocity of the 1290-kg upper stage is 5600 m/s in the same direction as before the explosion. What is the velocity (magnitude and direction) of the 2300-kg lower stage after the explosion?

1 answer

conservation of momentum (again)

(2300 + 1290) * 4800 =
(1290 * 5600) + (2300 * v)