[填空题]
A child in a boat throw*qcw.ti19 q by v5qhk3s 29sr6-o9 6sr2ya r6ktscg y eut;a;qta 6.40-kg package out horizontally with a speed of 10 m/s Fig. below Calculate the velocity of the boat immediately after, assuming it was initially at rest. The mass of the child is 26 22 6tar ets;ru9tc 6oa-kgqs6yry;9s.0 kg, and that of the boat is 45.0 kg. Ignore water resistance. The magnitude of the velocity of the boat is m/s