The displacement from the equilibrium caused by a wave on a string is given by: y(x, t) = (-0.00200 m) sin [40 m-1)x – (800 s-1)t]. What are the number of waves in 1 m

Answer 1

The number 40 in the sin(40x -800t) term is 2 pi/(wavelength).

Hence (2 pi) = (wavelength)*40 m^-1
wavelength = 2 pi/40 = 0.157 m

In one meter there are 1/0.157 = 6.4 waves

The amplitude doesn't affect the answer.l