Question

A 3.0 m solid copper rod is at 25°C. How long would it take sound to move through the rod from one end to another?

Responses

8.4×10^−4 s


2.9×10^−4 s


4.2×10^−4 s


4.5×10^−3 s

Answer 1

The answer is 4.2 × 10^-4 s.

The speed of sound in copper at 25°C is 3430 m/s. The length of the rod is 3.0 m. Therefore, it would take sound 3.0 m / 3430 m/s = 4.2 × 10^-4 s to move through the rod from one end to another.

So the correct response is 4.2 × 10^-4 s.