To determine who has the greatest velocity at 15 seconds, we need to analyze the distances traveled by each individual up to that point. Based on the provided graph coordinates, we look for the distance each person covered at the 15-second mark.
- Joy: Distance at 15 seconds (check the graph).
- Ivan: Distance at 15 seconds (check the graph).
- Shirley: Distance at 15 seconds (check the graph).
- Chris: Distance at 15 seconds (check the graph).
Once we have the specific distances at 15 seconds, velocity can be calculated using the formula:
\[ \text{Velocity} = \frac{\text{Distance}}{\text{Time}} \]
Since you have not provided the specific graph data, please refer to the graph and analyze the distance of each person at the 15-second mark to answer the question accurately.
If you have distance values for each of them at 15 seconds, I can help calculate their velocities and determine who has the greatest velocity.