The distance-time graph depicts the girl's movement, starting at the origin, rising to (20, 30), remaining flat until (35, 30), and then descending back to the origin.
Let's create a distance-time graph for the girl based on her walking and stopping intervals.
First Segment (Walking at 1.5 m/s for 20 seconds): During the initial 20 seconds, the girl walks at a steady speed of 1.5 m/s. The distance covered (d) during this time can be calculated using the formula "distance = speed × time." In this case, the distance covered is 30 meters.
Second Segment (Stopping for 15 seconds): During the next 15 seconds, the girl stops. The distance covered during this time is zero since she is not moving.
Third Segment (Walking back at 2 m/s): After the stop, the girl walks back to the start at a speed of 2 m/s. The time it takes to cover the initial 30 meters can be calculated using the formula "time = distance/speed." In this case, the time is 15 seconds.
Now, we can describe the distance-time graph. The x-axis represents time, and the y-axis represents distance. The graph will show a linear increase during the first 20 seconds, a flat line at 30 meters for the next 15 seconds, and a linear decrease back to the start in the final 15 seconds.
The graph consists of two line segments and a flat horizontal line. It starts at the origin, rises to (20, 30), stays flat until (35, 30), and then descends back to the origin.