The velocity of the mass after 9 second is 88 m/s
Radiated away as electromagnetic radiation.
We have the equation of motion
, where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.
Here displacement = 135 m, Initial velocity = 0 m/s, acceleration = 9.81
Substituting

A box falls out of a stationary helicopter hovering 135 m above the ground will take 5.25 seconds to reach the ground.
Kinetic energy per unit of mass is

Given, 
Therefore,


Now potential energy per unit mass is

Given, 
Therefore,


Thus, total mechanical energy of the river water per unit mass is


OR

It'll speed up in the direction it's being pushed unbalanced. Or, it could slow down if applied the right amount of unbalanced power. And finally if the unbalanced push is pushed it could change the direction of it's current motion it was traveling.<span>
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