Sound waves are

Options

A. transverse mechanical waves
B. longitudinal mechanical waves
C. neither (a) nor (b)
D. none of these

Answer

### Step-by-Step Solution:

1. **Understanding Sound Waves**:
- Sound waves are a type of mechanical wave that requires a medium (solid, liquid, or gas) to propagate. They cannot travel through a vacuum.

2. **Types of Waves**:
- Waves can be classified into two main types: transverse waves and longitudinal waves.
- **Transverse Waves**: In transverse waves, the oscillation of particles is perpendicular to the direction of wave propagation. For example, if a wave is moving in the x-direction, the particles move up and down in the y-direction.
- **Longitudinal Waves**: In longitudinal waves, the oscillation of particles occurs in the same direction as the wave propagation. This means if the wave is moving in the x-direction, the particles also move back and forth in the x-direction, creating areas of compression (where particles are close together) and rarefaction (where particles are spread apart).

3. **Identifying Sound Waves**:
- Sound waves are classified as longitudinal mechanical waves. This means that the particles of the medium through which sound travels oscillate in the same direction as the wave itself, resulting in compressions and rarefactions.

4. **Conclusion**:
- Given the definitions and characteristics of sound waves, the correct classification of sound waves is that they are longitudinal mechanical waves.

### Final Answer:
Sound waves are **longitudinal mechanical waves**.

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