longitudinal wave travels on a slinky or any long spring. The wave is represented by the equation $\mathrm{x}(\mathrm{x}, \mathrm{t})=2.1 \mathrm{~cm} \cos \left(2000 \mathrm{rad} / \mathrm{s} \mathrm{t}-40 \mathrm{~m}^{-1} \mathrm{x}\right)$. What is the direction of propagation of the wave?
A) the $-y$ direction
B) the $-x$ direction
C) the $+x$ direction
D) the $+\mathrm{y}$ direction

Question

Quizplus · Accepted Answer

The wave number is negative, so the wave is traveling in the positive x direction.

Longitudinal Wave Travels on a Slinky or Any Long Spring x(x,t)=2.1 cmcos⁡(2000rad/st−40 m−1x)\mathrm{x}(\mathrm{x}, \mathrm{t})=2.1 \mathrm{~cm} \cos \left(2000 \mathrm{rad} / \mathrm{s} \mathrm{t}-40 \mathrm{~m}^{-1} \mathrm{x}\right)x(x,t)=2.1 cmcos(2000rad/st−40 m−1x)

Longitudinal Wave Travels on a Slinky or Any Long Spring $\mathrm{x}(\mathrm{x}, \mathrm{t})=2.1 \mathrm{~cm} \cos \left(2000 \mathrm{rad} / \mathrm{s} \mathrm{t}-40 \mathrm{~m}^{-1} \mathrm{x}\right)$