Science lesson plan · 4th grade (Year 5 in England) · 45 minutes
Parts of a wave: crest, trough, amplitude and wavelength
Light, sound and waves
CCSS NGSS.4-PS4-1England: KS3 Physics: Waves (observed waves)
Objective and success criteria
Students will: Parts of a wave: crest, trough, amplitude and wavelength.
- 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: Pitch and loudness
Leads to: Measure and compare waves: amplitude and wavelength; Waves carry energy, not the water itself
Materials: Slinky or rope, Mirrors and torches, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Pitch and loudness). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- How do you make a drum sound louder? (hit it harder / hit it more gently / use a smaller drum / cover it with a cloth) → hit it harderPrompt: Bigger vibrations make louder sounds.
- Pitch and loudness: which statement is true? (Sounds get quieter the further you are from the source. / Longer strings make higher notes. / Hitting a drum harder makes a higher note. / Loud sounds always have a high pitch.) → Sounds get quieter the further you are from the source.Prompt: Pitch is about how fast; loudness is about how big.
- Pitch and loudness: which statement is NOT true? (Bigger vibrations make louder sounds. / Humans can hear sounds from about 20 Hz to 20 000 Hz. / Longer strings make higher notes. / Pitch is how high or low a sound is.) → Longer strings make higher notes.Prompt: Think about a long, low cello string.
Hook · 5 min
- Ask the class to make a wave with a rope or slinky and describe what moves and what doesn't.
- Share the objective: Parts of a wave: crest, trough, amplitude and wavelength. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: True or false? The crest is the top of a wave.
- Step 1: Yes: this matches what scientists observe.
- Step 2: So the answer is: True
- Answer: True
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- True or false? Wavelength is the height of a wave. (True / False) → FalsePrompt: Two are points (top and bottom); two are distances (across and up).
- True or false? The trough is the highest point of a wave. (True / False) → FalsePrompt: Two are points (top and bottom); two are distances (across and up).
You do: independent practice · 10 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 · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- True or false? Amplitude is measured from the middle line, not from the trough. (True / False) → TruePrompt: Two are points (top and bottom); two are distances (across and up).
- True or false? Amplitude is the distance from crest to crest. (True / False) → FalsePrompt: Two are points (top and bottom); two are distances (across and up).
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: Pitch and loudness.
- 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
- Move on to: Measure and compare waves: amplitude and wavelength; Waves carry energy, not the water itself.
- 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-4.
Free lesson plan from eurekami.com/lesson-plan-builder