MYP Physics · 01 · data analysis
Repeated timing of ten swings
Scientific inquiry and measurement · Original GioPhysics question with a detailed, mark-by-mark answer guide.
- Demand
- routine
- Marks
- 7
- Topics
- 2
- Answer
- Complete
A student times ten complete swings of the same pendulum five times. The stopwatch reads to 0.01 s.
| Trial | Time / s |
|---|---|
| 1 | 18.42 |
| 2 | 18.36 |
| 3 | 18.40 |
| 4 | 19.17 |
| 5 | 18.38 |
- a
Identify Identify the anomalous reading and give one evidence-based reason for your choice.
2 marks - b
Calculate Exclude the anomaly. Calculate the mean time for one swing and give the answer to an appropriate precision.
3 marks - c
Explain Explain why timing ten swings is better than timing only one swing with the same stopwatch.
2 marks
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a
Identify Identify the anomalous reading and give one evidence-based reason for your choice.
Read the data before explaining it. Quote the relevant values or trend, show the comparison or calculation, and then connect that numerical evidence to the physical conclusion—including uncertainty or anomalies when they matter.
- 1
Identifies 19.17 s as anomalous.
- 2
States that it is much farther from the tight cluster 18.36–18.42 s than any other reading.
b
Calculate Exclude the anomaly. Calculate the mean time for one swing and give the answer to an appropriate precision.
Read the data before explaining it. Quote the relevant values or trend, show the comparison or calculation, and then connect that numerical evidence to the physical conclusion—including uncertainty or anomalies when they matter.
- 1
Finds the mean time for ten swings: (18.42 + 18.36 + 18.40 + 18.38) ÷ 4 = 18.39 s.
- 2
Divides by ten to obtain the period 1.839 s.
- 3
Reports about 1.84 s with a justified precision.
c
Explain Explain why timing ten swings is better than timing only one swing with the same stopwatch.
Read the data before explaining it. Quote the relevant values or trend, show the comparison or calculation, and then connect that numerical evidence to the physical conclusion—including uncertainty or anomalies when they matter.
- 1
Human reaction-time uncertainty is roughly the same for either timing interval.
- 2
Dividing a longer total time by ten reduces the percentage uncertainty in the period.
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