Final answer:
The instantaneous velocity at t = 2 s for an object whose position vs. time graph is shown is zero since the slope of the graph at that point is zero, indicating that the object is not moving.
Step-by-step explanation:
To determine the instantaneous velocity of an object at a specific time using a position vs. time graph, you must look at the slope of the tangent line to the graph at that point in time. For the object described at t = 2 s, since the position remains constant for the first 2 seconds (the graph is a horizontal line), the slope of the tangent line (and therefore the instantaneous velocity) is zero. This means the object is stationary during this period.
The slope of a position vs. time graph represents the velocity of the object at that point. A horizontal line on such a graph indicates a slope of zero, thus a velocity of zero. Therefore, the velocity vs. time graph for this object would show a velocity of zero until t = 2 s.