A harmonic wave moving in the positive x direction has an amplitude of 3.1 cm, a speed of 37.0 cm/s, and a wavelength of 26.0 cm. Assume that the displacement is zero at x = 0 and t = 0.

Question

Calculate the displacement (in cm) due to the wave at x = 0.0 cm, t = 2.0 s.

Answer 1

The wave equation for deisplacement (Y)is

Y = (3.1 cm)* sin [2 pi)(x/L - f*t)]

f is the frequency, which is
(37 cm/s)/(26 cm) = 1.423 Hz

Insert x = 0 and t = 2s to compute the answer.

Answer 2

I'm still not getting the correct answer when I use the above formula. When I plugged in 0 for x and 2 for t, I simplified the equation to

Y= 3.1 * sin (2pi (-2.846))
Y=3.1 * sin (-17.88)
Y=3.1 * -.307
Y=-0.952 cm

What am I doing wrong?

Answer 3

nevermind, I was stupid and didn't have my calculator in radians! Thank!