A bomb explodes on the moon. How long will the sound take to reach the earth ?

Options

A. 10 seconds
B. 1000 seconds
C. 1 day
D. none of these

Explanation

To solve the question of how long it will take for the sound from a bomb explosion on the moon to reach the Earth, we need to consider the properties of sound and the environment between the moon and Earth.

### Step-by-Step Solution:

1. **Understanding Sound Propagation**:
- Sound is a mechanical wave that requires a medium (solid, liquid, or gas) to travel. It cannot travel through a vacuum.

2. **Identifying the Environment**:
- The space between the moon and the Earth is a vacuum. This means there are no air molecules or any other medium present.

3. **Conclusion on Sound Travel**:
- Since sound cannot travel through a vacuum, the sound produced by the bomb explosion on the moon will not reach the Earth at all.

4. **Final Answer**:
- Therefore, the time it would take for the sound to reach Earth is not measurable, as it will not travel through the vacuum. The correct option is "none of these."