Physics talent class activity.

Plan of capturing a video of a person walking in a straight line with a constant acceleration of 0.50/m s^2 for 5 seconds

Given: Meter rule, Masking tape, Software Tracker, stopwatch

Our plan:
Since acceleration is the change in velocity over time, we calculated the displacement of a person as time goes using S=Vt. We marked out areas using a meter rule and masking tape that a person must reach in each second. The person being filmed must pace himself such that in one second, he must reach the next marking and so on until the last one.

(our rough planning on paper)

Hypothesis: the displacement time graph would be in an increasingly increasing graph. The velocity time graph would be increasing constantly. The acceleration time graph would be a line with a gradient of 0

For the first second, the velocity is 0.50 m/s thus the person travels 0.50 m. For the second second, since acceleration is 0.50 m s^2, the velocity increases by 0.50 m/s to 1.00 m/s. The person then walks 1.000 m to a displacement of 1.50 m and so on. That is our calculations.

Results

Displacement time graph

Value of acceleration:0.3542 m s^-2

Velocity time graph

Value of acceleration: 0.4500 m s^-2

Acceleration time graph

Value of acceleration: 0.4011 m s^-2

Evaluation and conclusion

The results have not been quite close. The value of acceleration calculated from the best fit curve in displacement-time graph is 0.3542 m s^-2, far differing from the actual value of 0.50. It may be due to these sources of error such as random error due to human reaction time. For instance, we cannot reach each marking very accurately within each second as we have to look at the stopwatch also. Also, it may be due to wrong calculation. Our method theoretically makes the v-t graph like a stair-shape, instead of a smooth increasing line with a gradient of 0.50. This will definitely affect the a-t graph as the distance we travel is not actually the same. The other graphs' value of acceleration are least accurate from the S-t graph as many information of the actual values are gone when tracker decides to convert S-t graph to v-t and a-t graph.