A student takes a physics experiment by walking along a straight path. The student starts from a point O and walks with a constant velocity for 15 seconds. After that, the student stops and remains stationary for the next 5 seconds. Finally, the student turns around and walks back towards point O with a constant velocity for 10 seconds. The student's walking speeds are as follows: Constant velocity (first 15 seconds): 2 m/s Stationary (next 5 seconds): 0 m/s Constant velocity in the opposite direction (last 10 seconds): 3 m/s a) Create a displacement-time graph for the entire duration of the student's motion. b) Create a velocity-time graph that represents the student's motion