Question

which speed is at the sound barrier?
5 m/s
257 m/s
343 m/s
3.0 × 10⁸ m/s

Explanation:

The sound barrier refers to the speed of sound in dry air at 20°C, which is a standard value in physics. 5 m/s is a very slow speed (e.g., walking pace), 257 m/s is below the standard speed of sound, and $3.0 \times 10^8$ m/s is the speed of light in a vacuum, not sound.

Answer:

343 m/s