<h3><u>Answer;</u></h3>
11.7 m/s
<h3><u>Explanations;</u></h3>
Given:
M1 = 2,000kg, V1 = 14.0m/s
M2 = 1200kg, V2 = 21.0m/s
V3 = Velocity of M1, and M2 after colliding.
Momentum before = Momentum after.
M1×V1 + M2×V2 = M1*V3 + M2*V3.
2000×14 + 1200×21 = 2000V3 + 1200V3,
28,000+ 25,200= 3200V3,
Divide both sides by 3200:
V3 = 8.75 + 7.875 = -8.75 - 7.875i
<em><u>= 11.77 m/s</u></em>
The common velocity will be 11.77m/s, in the south west direction.