Question

a brass rod is encased in aluminum. what happens to the speed of a sound wave when it passes through the rod and moves from the brass into the aluminum?

a. its speed increases.
b. its speed decreases.
c. its speed stays the same
d. its speed falls to zero.

Explanation:

The speed of sound in brass is \(4700\) m/s and in aluminum is \(6420\) m/s. Since \(6420>4700\), when the sound wave moves from brass (lower speed) to aluminum (higher speed), its speed increases.

Answer:

A. Its speed increases.