An acoustics experiment is performed on a stretched steel wire of length 1.50 m fixed at both ends. A stationary wave is established when the wire is driven electromagnetically at its resonance frequency of 250 Hz.
The graph below shows the variation of displacement with distance from the left support at time t=0t = 0t=0. At this instant, all points on the wire have their maximum displacement. Q Q\,Q is a point on the wire.
The stationary wave is produced by two progressive waves travelling in opposite directions along the wire.
Deduce the amplitude of one of the progressive waves.
Determine the speed, in m s−1\text{m s}^{-1}m s−1, of one of the progressive waves.
State the phase relationship between the two progressive waves when t=0t = 0t=0.
For the point Q Q\,Q on the wire:
- calculate its oscillation period,
- state its amplitude of oscillation,
- describe its displacement-time behavior starting from t=0t = 0t=0.