Chapter 14, Problem 26PCE

Predict/Calculate Four waves are described by the following equations, in which all distances are measured in centimeters and all times are measured in seconds:

$\begin{array}{l}{y}_{\text{A}}=10\cos (3x-4t)\hfill \\ y_{\text{B}}=10\cos (5x+4t)\hfill \\ \begin{array}{l}{y}_{\text{C}}=20\cos (210x+60t)\\ y_{\text{D}}=20\cos (\text{24}x-\text{2}0t)\end{array}\hfill \end{array}$

(a) Which of these waves travel in the +x direction? (b) Which of these waves travel in the −x direction? (c) Which wave has the highest frequency? (d) Which wave has the greatest wavelength? (e) Which wave has the greatest speed?