A child in a boat throws a 5.30 kg package out horizontally with a speed of 10 m/s, see the figure. Calculate the velocity of the boat immediately after, assuming it was initially at rest. The mass of the child is 26.0 kg and that of the boat is 55.0 kg

What is the magnitude?

2 answers

Total linear momentum remains zero.

5.30 * 10 = -(26 + 55)*Vboat

Vboat = -0.6543 m/s
(opposite direction from thrown object)

Drop the minus sign for the magnitude.
It worked! You're awesome, thanks!