Sound and electricity
Bottles and bands: changing pitch and volume
What changes the pitch of a note, and what changes how loud it is?
Watch first
Feel how a vibration turns into a sound you can hear.
What you need
Tick each one as you find it — 0 of 4 ready.
Stay safe: Use plastic bottles if glass ones might get knocked over, and tap gently.
Plan the fair test
- Change: The amount of water, then how hard and how short you pluck
- Measure: The pitch and the volume of the note
- Keep the same: Same bottles, same spoon, same band
Objectives this evidences
- Find patterns between the volume of a sound and the strength of the vibrations that produced it
Do it, one step at a time
Step 1 of 4
- Step 1. Fill the bottles with different amounts of water and line them up from least to most.
- Step 2. Tap each one gently with the spoon and put them in order from lowest note to highest.
- Step 3. Now stretch the elastic band over the tub. Pluck it softly, then harder, and describe the difference.
- Step 4. Shorten the band by holding it partway along and pluck again. Note what changed this time.
What should happen
More water gives a lower tap note; plucking harder changes volume; shortening the band raises the pitch.
Think about: Which of your changes altered volume and which altered pitch? Keep the two words separate.
Write up your result
A sentence or two is enough to save it.
The lessons behind this practical
Each one opens with the same short film, and the film has a written transcript underneath if reading is easier than watching.
Now the quiz for this topic
Questions come from the lessons behind this practical, so nothing is asked that has not been taught.
Quiz
Sound and electricity quiz
8 questions from the lessons in this stage. No timer, and you can try again as many times as you like.