Describe apparatus, controlled variables and observations for stationary waves in (a) a stretched string, (b) microwaves and (c) an air column. Explain how positions/resonant lengths give wavelength. In the air-column experiment, successive resonances are at 0.170 m and 0.510 m with f=500 Hz. Find wavelength and sound speed, and give an uncertainty-reduction step and a safety step.

Question

Accepted Answer

String nodes and receiver minima have spacing λ/2; successive closed-tube resonances also differ by λ/2. λ=2(0.510−0.170)=0.680 m and v=500 × 0.680=340 m s⁻¹. Repeat/multiple intervals reduce fractional reading uncertainty; secure masses or keep water/electrics separated. String: vibrator/generator, tensioned string, tune frequency and measure stationary nodes with fixed tension. Microwaves: transmitter+reflector+movable receiver, fixed alignment/polarisation, record minima positions. Air: known-frequency source at variable-length closed tube, identify successive loud resonances; distinguish pressure from displacement nodes. Use λ/2 spacing correctly for all systems. Calculate 0.680 m and 340 m s⁻¹. Specify repeated/multiple-interval position processing and endpoint uncertainty. Give a relevant practical safety control.

Explain stationary-wave experiments, not just patterns

What a complete response should do

Your self-assessment