Question

question #17
which best describes the different media in which the speed of sound and light is the greatest?
light travels faster in solids, while sound travels faster in gases
light travels faster in gases, while sound travels faster in liquids
light travels faster in water, while sound travels faster in glass
light travels faster in gases, while sound travels faster in solids.
question #18
which of the following statements best describes the difference between electromagnetic and mechanical waves?
electromagnetic waves can travel only in one direction, while mechanical waves can travel in all directions.
electromagnetic waves travel at different speeds, while mechanical waves travel at the same speed
electromagnetic waves do not need a medium, while mechanical waves do need a medium.
electromagnetic waves produce sound, while mechanical waves can produce light.

Explanation:

For Question #17, light travels fastest in a vacuum and faster in gases compared to solids and liquids. Sound is a mechanical wave and travels fastest in solids as the particles are closely packed. For Question #18, electromagnetic waves are non - mechanical and can travel through a vacuum without a medium, while mechanical waves require a medium to propagate.

Answer:

Question #17: Light travels faster in gases, while sound travels faster in solids.
Question #18: Electromagnetic waves do not need a medium, while mechanical waves do need a medium.