Question

which statement correctly compares sound and earthquake waves?
○ sound waves and all earthquake waves have compressions and rarefactions
○ sound waves and all earthquakes waves have crests and troughs.
○ sound waves and some earthquake waves have compressions and rarefactions.
○ sound waves have crests and troughs and all earthquake waves have compressions and rarefactions

Explanation:

1. Recall wave types: Sound waves are longitudinal (have compressions/rarefactions). Earthquake has P - waves (longitudinal, compressions/rarefactions) and S - waves (transverse, crests/troughs), surface waves (transverse - like).
2. Analyze options:

• Option 1: “all earthquake waves” is wrong (S - waves/surface waves don't have compressions/rarefactions).
• Option 2: Sound is longitudinal (no crests/troughs), “all earthquake waves” is wrong.
• Option 3: Sound (longitudinal, compressions/rarefactions) and some earthquake waves (P - waves, longitudinal) have compressions/rarefactions. Correct.
• Option 4: Sound is longitudinal (no crests/troughs), “all earthquake waves” is wrong.

Answer:

Sound waves and some earthquake waves have compressions and rarefactions (the third option).