Walker, Halliday & Resnick — Waves-I: Problem 9

9 Two sinusoidal waves with the same amplitude of 6.00 mm and the same wavelength travel together along a string that is stretched along an x axis. Their resultant wave is shown twice in Fig. 16-24, as valley A travels in the negative direction of the x axis by distance d = 56.0 cm in 8.0 ms. The tick marks along the axis are separated by 10 cm, and height H is 8.0 mm. Let the equation for one wave be of the form $y(x, t) = y_m \sin(kx \pm \omega t + \phi_1)$, where $\phi_1 = 0$ and you must choose the correct sign in front of $\omega$. For the equation for the other wave, what are (a) $y_m$, (b) $k$, (c) $\omega$, (d) $\phi_2$, and (e) the sign in front of $\omega$?