Question 1203970
An object travelling in a straight line away from a motion sensor at a constant rate moves

 from 4 m away to 16 m away between t = 1 s and t = 6 s. 

Speed = (Change in Displacement ) / (Change in Time)

= (16-4)/(6-1)= 12/5

the object is moving away at a constant speed of 2.4 meters per second

Now if you draw a graph of speed Vs Time,  graph will be a horizontal line.

This line represents  the object as it moves from 4 meters to 16 meters away from the  sensor.