An experiment is done to investigate stationary waves on a string. A string of length 1.20 m1.20\text{ m}1.20 m is attached between a clamp stand and a vibration generator. A stationary wave is formed on the string when the vibration generator frequency is 400 Hz400\text{ Hz}400 Hz.
Figure 1 shows the variation of displacement with distance from one end of the string at time t=0t = 0t=0. At this time all points on the string have their maximum displacement. PPP is one point on the string.
The stationary wave is produced by two progressive waves travelling in opposite directions on the string.
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 waves when t=0t = 0t=0.
For the point PPP on the string, calculate its oscillation period, state its amplitude of oscillation, and describe its displacement-time behavior starting from t=0t = 0t=0.