The graph is a snapshot of a wave on a string. The wave travels to the right at $12\ \text{m/s}$. What is its frequency?

Fig. 1: A graph of displacement y in cm against position x in m, from 0 to 1.20 m, with marks at 0, 0.24, 0.48, 0.72, 0.96 and 1.20 m. A sine curve of amplitude 1.5 cm starts at zero, rises to a crest, crosses zero again at 0.24 m, reaches a trough, and is back at zero at 0.48 m. The pattern repeats two and a half times across the graph. A green arrow at the top points to the right, marked direction of travel.