To solve the question, "Inside a gas, sound transmission is possible for:", we will analyze the types of waves and their propagation in a gas medium.
### Step-by-Step Solution:
1. **Understanding Wave Types**:
- **Longitudinal Waves**: In longitudinal waves, the particles of the medium vibrate parallel to the direction of wave propagation. This means that as the wave travels, the particles compress and rarefy, creating areas of high and low pressure.
- **Transverse Waves**: In transverse waves, the particles of the medium vibrate perpendicular to the direction of wave propagation. This means that while the wave moves in one direction, the particles move up and down or side to side.
2. **Propagation of Sound in Gases**:
- Sound is a mechanical wave that requires a medium to propagate. In gases, the particles are relatively far apart compared to solids and liquids.
- For sound to travel through a gas, it relies on the compressions and rarefactions created by the longitudinal motion of gas particles. When one particle moves, it pushes against the neighboring particle, transferring energy in the same direction as the wave.
3. **Analysis of Longitudinal Waves in Gases**:
- In a gas, when a sound wave travels, it creates compressions (where particles are closer together) and rarefactions (where particles are further apart). The energy is effectively transferred from one particle to the next in the same direction as the wave.
- This mechanism allows sound to travel efficiently through gases.
4. **Analysis of Transverse Waves in Gases**:
- In contrast, for transverse waves, the particles would need to move up and down while the wave travels horizontally. However, in a gas, there is insufficient force of contact between particles to facilitate this type of motion. The particles cannot effectively transfer energy in a perpendicular direction, which is necessary for transverse wave propagation.
5. **Conclusion**:
- Since sound can only propagate as longitudinal waves in a gas due to the nature of particle interactions, we conclude that sound transmission inside a gas is possible only for longitudinal waves.
### Final Answer:
**Inside a gas, sound transmission is possible for longitudinal waves only.**
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