Answer:
(E)56.0 m/s
Explanation:
Height =h=-160 m
Because the wallet moving in downward direction
Time=t=7 s
Final speed of wallet=v=0
We have to find the speed of helicopter ascending at the moment when the passenger let go of the wallet.
Where 
Substitute the values
Option (E) is true
<h2>The option a is most appropriate </h2>
Explanation:
The total pressure due to liquid column at any place is the sum of
( i ) pressure due to liquid column called hydrostatic pressure
( ii ) the pressure due to air column above the liquid column , which is called the static pressure
Thus total pressure is the sum of hydrostatic and static pressure .
Thus the option a is most appropriate
the answer your looking for is Optical instrument.
