State the phase difference between R and T. phase difference = .................................................. ^{\circ}
On Fig. 4.1, draw an arrow at point T to show the direction in which point T is moving at the instant shown.
The horizontal separation between R and T is $0.62\,\text{cm}$, as shown in Fig. 4.2. The wave speed is $0.27\,\text{m s}^{-1}$. Calculate the frequency of the wave. frequency = .................................................. $\text{Hz}$
A water wave is generated by a dipper $S_1$ connected to a vibrator in a ripple tank. A matching dipper $S_2$ is also connected to the same vibrator. The two dippers create an interference pattern on the water in the tank, as shown in Fig. 4.3. The crests from each source are shown as solid lines on Fig. 4.3 and the troughs are shown as dashed lines. At point P in Fig. 4.3, the wave from $S_1$ has the same amplitude $A$ as the wave from $S_2$. Describe and explain the amplitude of the resultant wave at point P.