Answer:
The speed of combined package after the collision is [tex]\frac{\sqrt(2gh)}{4}\\[/tex].
Explanation:
mass of first package = m
height , h = 3 m
mass of second package = 3 m
let the speed of first package is u as it strikes with the second package.
Use the third equation of motion
[tex]v^2 = u^2 + 2 gh \\\\u^2 = 0 + 2 g h \\\\u = \sqrt {2gh}[/tex]
Let the velocity of combined package after the collision is v.
Use the conservation of momentum
[tex]m\times u + 3m \times 0= (m + 3m)\times v\\\\m u = 4mv \\\\v=\frac {u}{4}\\\\v = \frac{\sqrt(2gh)}{4}\\\\[/tex]