Answer:
A) - 1.8 m/s
Explanation:
As we know that whole system is initially at rest and there is no external force on this system
So total momentum of the system must be conserved
so we will have

now plug in all data into above equation



so correct answer is
A) - 1.8 m/s
Cloud Formation<span> Due to Surface Heating. Some </span>clouds<span>form due to the heating of the Earth's surface. First, the </span>Sun<span>heats the ground, which then heats the air. ... This extra water vapor begins to condense out of the air parcel in the form of liquid water droplets.</span>