Momentum
mava + mbvb = mava '+ mbvb'
(300 x 10)+(150 x 0) = (300 x 4.12)+(150 x vb')
3000=1236+150vb'
1764 = 150vb'
vb'=+11.76 m/s ≈ +11.8 m/s (positive sign, to the right)
Answer: 3
Explanation:
Given
One cloud is traveling at rate of 
combined velocity of the two is 
Suppose the masses of the clouds be 
Conserving momentum

Answer:
decreases.
Explanation:
When the aircraft is flies from the warm air into the colder air then its speed will be decreases.
as we know that
we know mach number is constant
so that here Mach number M is expressed as
M =
.............................1
here u is Local flow velocity with respect to the boundarie and v is the speed of sound in the medium
If the aircraft flies from hot air to cold air, the speed of sound in the medium will decrease. But the Mach number remains constant. Therefore, the local flow velocity relative to the boundaries also decreases.
Solid to liquid
Liquid to solid
By adding or removing heat energy aka thermal energy