The velocity $v$ of a wave can be calculated using the formula:

$v = f \cdot \lambda$

Where:

• $f$ is the frequency of the wave.
• $\lambda$ is the wavelength of the wave.

Given:

• $f = 400 \, \text{Hz}$
• $\lambda = 30 \, \text{m}$

Substitute these values into the formula:

$v = 400 \cdot 30$

$v = 12,000 \, \text{m/s}$

Final Answer:

The velocity of the sound wave is $12,000 \, \text{m/s}$.

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Related Questions:

1. What is the formula for calculating wave velocity in different mediums?
2. How does the medium affect the speed of a sound wave?
3. What is the relationship between frequency, wavelength, and speed?
4. Can you explain the difference between transverse and longitudinal waves?
5. How does temperature influence the velocity of sound in air?

Tip:

Always check the units of your given values to ensure consistency when solving wave-related problems!