Final answer:
Determining the runner's instantaneous velocity at t = 120 s requires a velocity vs. time graph or a function describing motion. As this information is lacking, the velocity cannot be calculated accurately without additional data.
Step-by-step explanation:
The student's question is about finding the instantaneous velocity of a runner at a given time t = 120 seconds. Without the velocity versus time graph or a mathematical function describing the runner's motion provided, to determine the runner's instantaneous velocity at t = 120 s, one would typically derive it from the position vs. time graph or use the derivative of the position function if known. The slope of the velocity vs. time graph at that point would give the runner's instantaneous velocity.
However, since the exercise provided does not include sufficient information to solve for the instantaneous velocity at t = 120 s, we cannot accurately determine it. Typically, you would look at the provided graph of velocity vs. time and find the value of the graph at t = 120 s or use a mathematical function, if available, to compute the derivative at t = 120 s.
To accurately answer this question, the specific velocity vs. time graph or a functional form of the position or velocity with respect to time needs to be referenced.