Describe how the apparatus should be set up so that the waves from the dippers are coherent.
State one other condition that must be met by the waves for the interference pattern to be observable.
Light from a lamp above the ripple tank passes through the water onto a screen below the tank. Describe one way of seeing the illuminated pattern more clearly.
The waves travel at $0.40\,\text{m s}^{-1}$. Calculate the period of the waves.
Fig. 5.1 shows point X that lies on a crest of the wave from D1 and halfway between two neighbouring crests of the wave from D2. For the waves at point X, state the path difference, in $\text{cm}$.
At point X, state the phase difference for the waves.
On Fig. 5.1, draw one line, at least $4\,\text{cm}$ long, that links points where only maxima of the interference pattern are seen.
Fig. 5.1 shows point X that lies on a crest of the wave from D1 and halfway between two adjacent crests of the wave from D2. For the waves at point X, state: (i) the path difference, in $\text{cm}$ (ii) the phase difference.