A transverse wave on a string is described by the equation

y(x,t) = (2.20cm) sin [(130 rad/s)t+ (15rad/m)x]

We have to find the speed of wave moving along the string .

I tried as

$\omega = 130 , k=15 =\omega /v =(130)/(v) $ and v =26

But the answer is given as 8.7 m/s