A transverse wave is propagated in a string stretched along the x-axis. The equation of the wave, in SI units, is given by:
y = 0.005 cos [π (38t - 14x)].
(a) The wave speed, including the sense of direction along the x-axis, in SI units, is closest to .

The wave speed in SI units, is closest to - 2.7 m/s

Explanation:

given information:

y = 0.005 cos [π(38t - 14x)]

we know that the wave function is

y =  A cos (kx ± ωt)

where

A = amplitude

w = angular velocity

k = wave number

thus,

y = 0.005 cos [(14πx - 38πt)]

ω = - 38π

k = 14π

to find the speed v, we use the equation below

v = ω/k

so,

v = - 38π/14π

  = - 2.7 m/s