Physics and Sports Analysis

Solutions

1. The runner’s speed is zero at the starting point A

2. Speed = Distance / Time

Speed(pt. B) = 10m / t(pt.B)

Speed(pt. C) = 10m / t(pt.C) – t(pt B)

3. There will be 3 points on the graph for each runner, corresponding to the measurements taken at points A, B and C. The slope of each segment of the line is equal to the speed of the runner.

Slope (m) = (Y2-Y1) / (X2-X1)

4. The direction in which point B is in relation to point A needs to be determined (N, S, E, W, or a combination). This direction needs to be added to the speed at that point to give the velocity.

e.g. If the speed is 3m/s, the velocity could be : 3m/s NW

5. Acceleration = final speed – initial speed / t

[AB] = final speed – 0 / 0 = 0

[BC] = speed (pt C) – speed (pt B) / t (pt C) – t (pt B)

6. From the graph you should be able to see who reached the 20m in the least amount of time, making them the fastest or the person with most speed.

From the graph, the more vertical the line is, the faster the person was moving between points. If there were a few runners, you can see if skipping or speed-walking was quicker for most or all of them.

7. On the graph you need to extrapolate or extend the line in the same direction that it is between points B and C. First you need to mark off where 3 additional seconds would be on the x-axis after the last graphed point. Draw a vertical line upward from this mark on the x-axis. Now continue the original graphed line until it meets the vertical line you just drew. This is how far your runner would have skipped to, if they had continued for 3 more seconds. Take a reading on the y-axis at this new intersection point to find the exact distance covered. This is your answer in metres.