Question

1. draw a position - time graph illustrating the following story below. a person starts from rest and walks for 5 minutes and covers two blocks at a moderate but constant speed, then walks the next 2 blocks more slowly and takes 10 minutes, then rests for 5 minutes, takes 10 more minutes to walk back 1 block and finally accelerates from rest and covers the remaining blocks in only 5 minutes.

Explanation:

Step1: First walking segment

The person starts from rest and walks 2 blocks in 5 minutes at a constant speed. On a position - time graph, this is a straight - line with a positive slope. The starting point is (0,0) and the ending point of this segment is (5,2).

Step2: Second walking segment

Then the person walks 2 more blocks in 10 minutes at a slower constant speed. The starting point of this segment is (5,2) and the ending point is (5 + 10,2+2)=(15,4).

Step3: Resting segment

The person rests for 5 minutes. During rest, the position does not change. So, the starting point is (15,4) and the ending point is (15 + 5,4)=(20,4).

Step4: Third walking segment

The person walks back 1 block in 10 minutes. The starting point is (20,4) and the ending point is (20 + 10,4 - 1)=(30,3).

Step5: Fourth walking segment

The person accelerates from rest and covers the remaining 3 blocks in 5 minutes. The starting point is (30,3) and the ending point is (30 + 5,3+3)=(35,6).

To draw the graph:

1. Mark the points (0,0), (5,2), (15,4), (20,4), (30,3), (35,6) on the position - time graph.
2. Connect the points with straight - line segments for the constant - speed and resting parts. For the accelerating part, the line will be a curve (but for a simple illustration of the overall motion, a straight - line can also be used to approximate the general trend of increasing position over time).

Answer:

The position - time graph has points (0,0), (5,2), (15,4), (20,4), (30,3), (35,6) connected by appropriate line segments as described above.