A crest of a sinusoidal wave on a stretched string is located at x=0 at t=0. At t=0.03s the same crest is observed at x=0.12m towards the right. If the wavelength of the wave is 0.48m, determine:
a. (i) the speed of propagation
b. (ii) the frequency of the wave
c. (iii) the direction of travel