Question

how are electromagnetic and mechanical waves different?
electromagnetic waves can travel through a vacuum, but mechanical waves cannot.
mechanical waves can travel through a vacuum, but electromagnetic waves cannot.
electromagnetic waves travel slower than mechanical waves.

Explanation:

To determine the difference between electromagnetic and mechanical waves, we analyze each option:

1. Electromagnetic waves (e.g., light) can travel through a vacuum as they don't need a medium. Mechanical waves (e.g., sound) require a medium (like air, water, or solids) and thus can't travel through a vacuum.
2. The second option is incorrect because it reverses this property.
3. The third option is incorrect because electromagnetic waves (like light in a vacuum) travel much faster than most mechanical waves (e.g., sound in air).

Answer:

A. Electromagnetic waves can travel through a vacuum, but mechanical waves cannot.