| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Physics |
| Lesson Topic: Describe a method involving a measurement of distance and time for determining the speed of sound in air |
Learning Objective/s:
- Describe the method of measuring distance and time to determine the speed of sound in air.
- Calculate the speed of sound using v = d⁄t and propagate measurement uncertainties.
- Analyse experimental data to obtain an average value and compare it with the theoretical speed.
- Evaluate sources of error and suggest practical improvements.
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Materials Needed:
- Long straight hallway or track (≥15 m)
- Two identical loudspeakers or a speaker and microphone
- Electronic timer/stopwatch with millisecond resolution
- Measuring tape or laser distance measurer
- Computer with data‑logging software (optional)
- Temperature sensor or thermometer
- Worksheet or data table for recording results
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Introduction:
Begin with a quick demonstration of a balloon pop echoing across the classroom to spark curiosity about how fast sound travels. Review the relationship v = d⁄t and remind students of prior work with distance‑time graphs. Explain that today they will design and carry out a hands‑on experiment to measure the speed of sound, and success will be shown by producing a value within 5 % of the theoretical speed.
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Lesson Structure:
- Do‑now (5'): Students answer a short question on how distance and time relate to speed (check understanding).
- Mini‑lecture (10'): Recap v = d⁄t, discuss temperature effects, introduce apparatus (brief Q&A).
- Group setup (10'): Teams set up speakers, microphone, and measure the first distance (5 m); verify timer connection.
- Data collection (15'): Perform three trials at each of three distances (5 m, 10 m, 15 m), recording times; rotate roles.
- Data analysis (10'): Calculate speed for each trial, compute averages, propagate uncertainties, compare with theoretical value.
- Reflection (5'): Groups discuss error sources and possible improvements; teacher provides feedback.
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Conclusion:
Summarise how the experiment used repeated distance‑time measurements to yield a reliable speed of sound. Ask each group to write one exit‑ticket sentence stating their final average speed and one improvement they would make. For homework, assign a short problem calculating the expected speed at a given temperature and comparing it to their measured value.
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