Question

1. which graph would best depict the following scenario? a man starts at the origin, walks back slowly and steadily for 6 seconds. then he stands still for 6 seconds, then walks forward steadily about twice as fast for 6 seconds. note that these are velocity - time graphs.
2. for the same scenario as #2, which position - time graph best depicts the motion?

Explanation:

Step1: Analyze the velocity - time graph for the first 6 seconds

The man walks back slowly and steadily for 6 seconds. This means the velocity is negative and constant for the first 6 seconds.

Step2: Analyze the velocity - time graph for the next 6 seconds

He stands still for 6 seconds. So the velocity is 0 for the time interval from 6 - 12 seconds.

Step3: Analyze the velocity - time graph for the last 6 seconds

He walks forward steadily about twice as fast for 6 seconds. So the velocity is positive and has a larger magnitude than the initial negative velocity for the time interval from 12 - 18 seconds. The correct velocity - time graph is B.

Step4: Analyze the position - time graph

For the first 6 seconds (while walking backward), the position is decreasing linearly. For the 6 - 12 seconds (standing still), the position remains constant. For the 12 - 18 seconds (walking forward faster), the position increases linearly at a steeper rate than it decreased initially. The correct position - time graph is B.

Answer:

1. B
2. B