In which scenario can light travel but sound cannot?

In which scenario can light travel but sound cannot?

• A. In a vacuum, light travels; sound cannot travel.
• B. In air, light travels; sound cannot travel.
• C. In vacuum, both light and sound travel.
• D. In water, light cannot travel; sound travels.

Answer: (A)

Light and sound move differently because light is an electromagnetic wave that can travel through empty space, while sound is a mechanical wave that needs particles to carry vibrations. In a vacuum there are no particles, so sound cannot travel, but light can propagate through the emptiness. That’s why light traveling in a vacuum while sound does not is the scenario that fits. In air, both light and sound can travel, and in water both can travel too (though light slows and refracts).

Light and sound move differently because light is an electromagnetic wave that can travel through empty space, while sound is a mechanical wave that needs particles to carry vibrations. In a vacuum there are no particles, so sound cannot travel, but light can propagate through the emptiness. That’s why light traveling in a vacuum while sound does not is the scenario that fits. In air, both light and sound can travel, and in water both can travel too (though light slows and refracts).