Kinematics lab question

Question

Procedures

1. Lay out a 50 meter course marking the ground every 5 meters. Leave 10 meters before and after the course for speeding up and slowing down.
2. Position one timer and one data recorder at each 5 meter mark and an announcer at the starting line.
3. One data collection run will occur as follows:
4. A runner starts running approximately 10 meters before the start line, making sure to reach a constant speed before reaching the start line.
5. The runner runs at a constant speed until after the 50 meter mark is passed, then the runner may slow down.
6. As the runner passes the start line, the announcer signals all of the timers to start timing.
7. As the runner passes each 5 meter mark, the timer at that mark will stop timing and that time is recorded for that position.
8. Collect data for 4 different types of runners:
9. walk
10. jog
11. run
12. sprint
13. Share all data on the following tables
14. Make a graph with position on the vertical axis (y-axis) and time on the horizontal axis (x-axis). Plot all four trials on the same graph.

Questions:

What would be the physical meaning of the slope? Explain.

Would the y-intercept be 0? Explain.

Should (0,0) be a point on the graph? Explain

In which run was the speed most constant? How can you tell?

Answer 1

(1) What would be the physical meaning of the slope? Explain.

The slope is the speed of the runner because this is the distance divided by the time. As we know the speed is the distance covered in the one unit of time.

(2) Would the y-intercept be 0? Explain.

Yes, because the announcer starts counting of the time when the runner is at the start y = 0.

(3) Should (0,0) be a point on the graph? Explain.

Yes, as it explained in the answer to question (2).

(4) In which run was the speed most constant? How can you tell?

The speed is a slope on the graph. The slope on the straight line is constant. Therefore, the closer the graph is to the straight line the more constant is the speed.