Science lesson plan · 7th grade (Year 8 in England) · 60 minutes
Speed of sound and echoes
Light, sound and waves
CCSS NGSS.MS-PS4-1England: KS3 Physics: Waves (sound waves)
Objective and success criteria
Students will: Speed of sound and echoes.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Sound comes from vibrations; Speed = distance ÷ time
Leads to: the next skill in this area.
Materials: Slinky or rope, Mirrors and torches, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 6 min
- Quick retrieval from earlier learning (Sound comes from vibrations; Speed = distance ÷ time). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- What makes the sound when you pluck a guitar string? (the string getting hot / light from the string / the wood breathing / the string vibrating) → the string vibratingPrompt: Touch the string gently after plucking it.
- A dog travels 80 m in 8 s. What is the average speed, in m/s? → 10 m/sPrompt: speed = distance ÷ time
- Sound: which statement is true? (Sound travels through space between planets. / Loud sounds do not involve vibrations. / Sound cannot travel through water. / Sound cannot travel through empty space (a vacuum).) → Sound cannot travel through empty space (a vacuum).Prompt: Can sound travel where there is nothing at all?
Hook · 6 min
- Ask the class to make a wave with a rope or slinky and describe what moves and what doesn't.
- Share the objective: Speed of sound and echoes. Read the success criteria together.
I do: model it · 12 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: You see lightning and hear the thunder 2 seconds later. Sound travels at about 340 m/s. About how far away is the storm, in metres?
- Step 1: 340 × 2 = 680
- Step 2: So the answer is: 680 m
- Answer: 680 m
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 12 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- You see lightning and hear the thunder 6 seconds later. Sound travels at about 340 m/s. About how far away is the storm, in metres? → 2040 mPrompt: Light arrives almost instantly; the delay is the sound travelling.
- You shout towards a cliff and hear the echo 2 s later. Sound travels at 340 m/s. How far away is the cliff, in metres? → 340 mPrompt: The sound goes to the cliff and back.
You do: independent practice · 17 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 7 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- You see lightning and hear the thunder 5 seconds later. Sound travels at about 340 m/s. About how far away is the storm, in metres? → 1700 mPrompt: Light arrives almost instantly; the delay is the sound travelling.
- You shout towards a cliff and hear the echo 0.5 s later. Sound travels at 340 m/s. How far away is the cliff, in metres? → 85 mPrompt: The sound goes to the cliff and back.
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Sound comes from vibrations.
- Use concrete materials: slinky or rope.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-7.
Free lesson plan from eurekami.com/lesson-plan-builder