A transverse periodic wave is represented by the equation y(x, t) = 2.50 cm cos(2,500 rad/s t − 15.0 m⁻¹ x). What is the direction of the vibration of the wave? A) the z direction B) the y direction C) the x direction

Question

Quizplus · Accepted Answer

The cosine function in the equation represents the amplitude of the wave at a given point in space (x) and time (t). The argument of the cosine function, which is (2,500 rad/s)t - 15.0 mS⁻¹x, represents the phase of the wave at that point in space and time. 
The fact that the x variable is multiplied by a negative value (-15.0 mS⁻¹) indicates that the wave is travelling in the positive x-direction. The cosine function indicates that the vibration of the wave is in the y-direction because the amplitude varies with the cosine function as opposed to the sine function, which would indicate vibration in the x-direction. Therefore, the correct answer is B, the y direction.

A Transverse Periodic Wave Is Represented by the Equation Y(x