Two observations are made of a traveling wave on a string.
• At time t = 0, a displacement–versus–position graph shows consecutive crests at x = 0 cm and x = 30 cm.
• At position x = 0 cm, a displacement–versus–time graph shows that successive crests pass that point 0.40 s apart.
Using these observations, what is the speed of the wave?
a) 1.5m/s
b) 7.5m/s
c) 0.75m/s
d) 0.12m/s