What quantity did you change?
Labs / Physics
Standing Waves
A string is clamped at both ends and shaken at one end. Most frequencies just wobble and wash out — but hit a harmonic and the outgoing and reflected waves superpose into a still pattern of nodes and antinodes. Sweep the frequency and tension, or grab the string to pluck it, and watch the pattern lock in.
Labs / Physics / Standing Waves
Standing Waves
A string is clamped at both ends and shaken at one end. Most frequencies just wobble and wash out — but hit a harmonic and the outgoing and reflected waves superpose into a still pattern of nodes and antinodes. Sweep the frequency and tension, or grab the string to pluck it, and watch the pattern lock in.
Why it matters
Why explore this?
Physics explains how changes in forces, energy, motion, and matter produce results we can measure. This model lets you test one part of that relationship at a time.
Explore
Try the model
harmonic n = 1v 12.6 m/snodes 2gain ×1.0
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- Slide the frequency slowly upward. Why does the string only stand still at certain sharp values, and go quiet in between?
- Each time the pattern locks in, count the antinodes. How does that number relate to the harmonic readout?
- Tighten the tension. The wave speed climbs — so does the same frequency still land you on the same harmonic, or a different one?
- Turn on harmonic snap and sweep again. What does the string do now that it never falls between harmonics?
- Crank the damping all the way up. What happens to the height of the antinodes, and to how sharply the resonance picks out a frequency?
Explain
Make sense of what happened
Name the quantity you changed, the quantity that responded, and the physical rule connecting them. Use a readout or visible change as evidence.
Check
Before you leave
What measurable result changed?
Which physical idea connects them?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.