The position in the graph between 4 - 6 seconds is the region of constant velocity.
<h3>What is constant velocity?</h3>
The term constant velocity refers to the period in the graph when the velocity is not changing with time. As such, the graph is shown to be a flat portion at such a point.
Hence, it follows that the position in the graph between 4 - 6 seconds is the region of constant velocity.
Objects dropped straight or thrown horizontally from the same height change their vertical velocity at the same rate, and fall through equal vertical distances in equal time intervals.