Graph for helicopter at 2000 meters descends at 2 meters per second.

We are asked to provide a graph for a model describing a helicopter descending from 2000 meters at 2 meters per second.
We recognize that the rate of change (2 meters per second) is constant, so the model is linear and the graph will be a line.
A line can be described algebraically as y=mx+b where each (x,y) coordinate is determined from the initial point b (where x is zero) and the slope m (the constant rate of change.)
Here m=-2 and b=2000 so we have y=-2x+2000
The graph:

Here the horizontal axis represents time in seconds, and the vertical axis is distance from the ground in meters.
Note that the slope is consistent, -2/1, regardless of the units along the axes.
Hope this has been a help.