Question

A progressive wave is given by y (x, t) = 8 cos (300 t - 0.15 x) where x and y are in m andt in second. What is its wavelength, frequency and wave speed?​

Answer 1

the standard equation of a progressive wave is given by,

y(x,t) =Acos(wt-kx)

comparing this equation with equation given in question,

A = 8m

w=300 rad/s

k=0.15m

now,

w=2πf = 300

thus, f= 300/2π = 47.78 Hz

k= 2π/wavelength

thus, wavelength = 2π/0.15 = 41.86 m

wave speed = w/k = 300/0.15 = 2000m/s