Sound: String Length and Pitch | Virtual Science Teachers

Sound: String Length and Pitch

Pluck the strings of a virtual harp to investigate what makes a sound high or low.

Investigate this question

How does the length of a harp string affect the pitch (frequency) of the sound it makes?

How to use this

  1. Click a string, or use a note button, to pluck it.
  2. Watch it vibrate and listen to the pitch.
  3. Read that string's length and frequency.
  4. Compare a long string to a short one.
  5. Use your data as evidence for the question.

Options

Last string plucked

Length
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Frequency
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Pluck a string

Your data

Pluck a string to start collecting data.

Background

Key vocabulary
Vibration
A repeated back and forth motion. Plucking a string causes it to vibrate.
Pitch
How high or low a sound seems to your ear.
Frequency (Hz)
How many vibrations happen each second, measured in hertz.
Amplitude
The size of a vibration. Bigger amplitude usually sounds louder.
Wave
A disturbance that transfers energy from one place to another.
Transverse wave
A wave where the material moves perpendicular to the direction the wave travels. The vibrating string is a transverse wave.
Longitudinal wave
A wave where the material compresses and spreads parallel to the direction the wave travels. Sound moving through air is a longitudinal wave.
Science concepts

When a harp string is plucked, it begins to vibrate, and that vibration is what produces sound.

  • Plucking a string transfers energy to the string and starts its vibration.
  • The vibration pattern on a string is a type of standing wave, because the wave reflects back and overlaps with itself between the fixed ends.
  • The frequency of the vibration is what determines the pitch you hear.
  • Strings vibrate differently depending on length, thickness, and tension.
  • In this simulation, thickness and tension stay the same, so you can focus on how length alone affects pitch.

Write your CER

You are answering this question

How does the length of a harp string affect the pitch (frequency) of the sound it makes?

Claim

Write one clear sentence that answers the question.

Sentence starter

When the string length ____________, the pitch and frequency ____________.

Evidence

Use data from the simulation to support your claim. Include at least two specific examples with string lengths and frequencies.

Sentence starter

In the simulation, when I plucked a string with length ______, its frequency was ______ Hz.

When I plucked a shorter string with length ______, its frequency was ______ Hz.

Reasoning

Explain why the pattern happens, using science ideas about vibrations. Connect string length to vibration rate to frequency to pitch.

Sentence starter

This evidence supports my claim because ____________.