A transverse wave travels along a stretched string.
(i) A fixed point on the string completes 15 complete oscillations in 3.0s. Calculate the frequency and the period of the wave.
(ii) The measured distance between two successive crests on the string is 0.40m. Using an appropriate relation, determine the speed of propagation of the wave.
(iii) If the time period of the wave were suddenly halved while the wavelength remained unchanged, what would be the new speed of the wave? Justify your answer mathematically.