Abox falls out of a stationary helicopter hovering 135 m above the ground. how long will it take to hit the ground?

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.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

read more on -

explanation:

as the height from which the ruler was dropped increased, the speed of the ruler at ryan's hand increased.