A wave is represented by the equation
y = (0.001 mm) sin[(50 s−1)t + (2.0 m−1)x].
The frequency = 25π Hz.
Comparing with the standard equation,
y = A sin (ω t+kx)
ω = 2 π f = 50
f= 25π Hz
Amplitude is A= 0.001 mm.
K = 2 =2 πλ
λ= π m
v = wk = 502 = 25 m s−1.