Question 24

The speed of sound in empty space is 0 km/s.

In empty space, the speed of sound is 0 km/s because sound requires a medium (such as air, water, or solids) to propagate. Since a vacuum contains no matter, sound cannot travel through it.

A) 0 km/s

This option is correct as it accurately reflects the fact that sound cannot travel in a vacuum. Without a medium, sound waves have no means of propagation, resulting in a speed of zero.

B) greater than 0 but less than 300,000 km/s

This option is incorrect because it suggests that sound can travel in a vacuum at a non-zero speed. Since sound requires a medium to propagate, it cannot exist in empty space at any speed.

C) 300,000 km/s

This option is incorrect as well. It conflates the speed of light with the speed of sound. The speed of light is indeed 300,000 km/s in a vacuum, but sound does not travel in a vacuum at any speed, including this one.

D) greater than 300,000 km/s

This option is also incorrect. It incorrectly implies that sound can travel faster than the speed of light in a vacuum, which is not possible as sound cannot travel in a vacuum at all.

Conclusion

The correct answer is 0 km/s because sound cannot propagate in empty space, while all other options incorrectly suggest that sound can travel at some speed in a vacuum. This distinction is crucial in understanding the fundamental differences between light and sound propagation.