Answer:
The velocity of mass 2m is 
Explanation:
From the question w are told that
The mass of the billiard ball A is =m
The initial speed of the billiard ball A =
=1 m/s
The mass of the billiard ball B is = 2 m
The initial speed of the billiard ball B = 0
Let the final speed of the billiard ball A = 
Let The finial speed of the billiard ball B = 
According to the law of conservation of Energy

Substituting values

Multiplying through by 

According to the law of conservation of Momentum

Substituting values

Multiplying through by 

making
subject of the equation 2

Substituting this into equation 1




Multiplying through by 



Solution :
Speed of the air craft,
= 262 m/s
Fuel burns at the rate of,
= 3.92 kg/s
Rate at which the engine takes in air,
= 85.9 kg/s
Speed of the exhaust gas that are ejected relative to the aircraft,
=921 m/s
Therefore, the upward thrust of the jet engine is given by

F = 85.9(921 - 262) + (3.92 x 921)
= 4862635.79 + 3610.32
= 
Therefore thrust of the jet engine is
.
Answer:


Explanation:
Height Of the watermelon when it is dropped is given as

time of fall under gravity

now if water melon start from rest then we have

acceleration due to gravity for watermelon

now we need to find the final speed of watermelon

so we will have

