Q.15.13 Given below are some functions of x and t to represent the displacement (transverse or longitudinal) of an elastic wave. State which of these represent (i) a travelling wave, (ii) a stationary wave or (iii) none at all:
(a) It represents a stationary wave.
(b) The given function does not represent a wave as we can see at certain values of x and t the function would not be defined.
(c) It represents a travelling wave.
(d) It represents a stationary wave. It is a superposition of two stationary waves which ultimately results in another stationary wave.