as soon as the mail packet is thrown first it moves upward with the same velocity of that of the helicopter and then decreases due to gravity.first the velocity is equal to that of 2m/s & then decreases

 

this is because of newtons first law of motion: a bodywhich is moving continous to move unless it is acted upon by an external force

 

Here the external force is gravity. The mail packet when thrown from the helicopter it moves with the velocity equal to that of the helicopter & then decreases. hope u got somthing

 

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