Position vs. Time Graphs Position versus time graphs for boats traveling along a narrow channel are shown below. The scales on
both axes are the same for all of these graphs. In each graph, a point is marked with a dot.

a) For which of these, if any, is the position zero at the indicated point?

b) For which of these, if any, is the position negative at the indicated point?

c) For which of these, if any, is the velocity zero at the indicated point?

d) For which of these, if any, is the velocity negative at the indicated point?