PSS 4.1 PART B.
ANSWER:
At ground level below the point where the rock is launched.
EXPLANATION:
It's best to place the origin of the coordinate system at ground level below the launching point because in this way all the points of interest (the launching point
and the landing point) will have positive coordinates. (Based on your experience, you know that it's generally easier to work with positive coordinates.) Keep in
mind, however, that this is an arbitrary choice. The correct solution of the problem will not depend on the location of the origin of your coordinate system.
Now, define symbols representing initial and final position, velocity, and time. Your target variable is , the initial y coordinate of the rock. Your pictorial
representation should be complete now.