MYP Physics · 20 · data analysis
Find the anomaly in a wave-speed study
Independent assessment practice · Original GioPhysics question with a detailed, mark-by-mark answer guide.
- Demand
- demanding
- Marks
- 8
- Topics
- 2
- Answer
- Complete
Students change the frequency of a wave generator on the same stretched cord. They measure wavelength and calculate wave speed.
| Frequency / Hz | Wavelength / m | Calculated speed / m s⁻¹ |
|---|---|---|
| 5.0 | 2.40 | 12.0 |
| 7.5 | 1.60 | 12.0 |
| 10.0 | 1.18 | 11.8 |
| 12.5 | 1.20 | 15.0 |
| 15.0 | 0.81 | 12.2 |
- a
Verify Verify the calculated speed for the 10.0 Hz reading.
2 marks - b
Identify Identify the anomalous row and justify your decision quantitatively.
3 marks - c
Evaluate Evaluate the conclusion that frequency changes wave speed on this cord.
3 marks
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a
Verify Verify the calculated speed for the 10.0 Hz reading.
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
Uses v = fλ.
- 2
Calculates v = 10.0 × 1.18 = 11.8 m s⁻¹.
b
Identify Identify the anomalous row and justify your decision quantitatively.
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 the 12.5 Hz row.
- 2
States that its calculated speed is 15.0 m s⁻¹ while the other results cluster around 12.0 m s⁻¹.
- 3
Quantifies the difference, for example 3.0 m s⁻¹ or about 25% above 12.0 m s⁻¹.
c
Evaluate Evaluate the conclusion that frequency changes wave speed on this cord.
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
States that the non-anomalous data support approximately constant speed as frequency changes.
- 2
Explains that wavelength decreases as frequency increases so fλ remains nearly constant.
- 3
Suggests repeating the anomalous measurement and controlling tension, because tension or measurement error could explain the difference.
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