A position versus time graph is shown below. A Position versus Time graph is shown with y-axis labeled position in meters north up to 20 and x-axis labeled time in seconds up to 10. A line connects points 0, 0 and 1, 4. A horizontal line connects points 1, 4 and 4, 4. A line connects points 4, 4 and 6, 10. A horizontal line connects points 6, 10 and 8, 10. A line connects 8, 10 and 9, 14, and then 10, 15. Use the graph to determine the instantaneous velocity in m/s of the object at 3 seconds. a 4 m/s north b 3 m/s north c 1.3 m/s north d 0 m/s north