Arock is dropped from a height of 80 m and is in free fall. what is the velocity of the rock as it reaches the ground 4.0 seconds later?

Here is the solution below:

V = s / t

Where, S is the displacement and
             t is the time taken.
Since displacement is expressed in meters and time taken in seconds. Velocity is expressed in meters/second or m/s.

V = 80m / 4.0 secs
V = 20 m/sec

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