Question

unit 7 \physical interaction\ test
the amplitude of a compressional wave depends on the
○ density of material in compressions and rarefactions
○ number of wavelengths that pass by a point each second.
○ distance between crests and troughs.
○ vibration of electric and magnetic parts.

Explanation:

The amplitude of a compressional wave is related to the density of material in compressions and rarefactions. Higher density differences in compressions and rarefactions mean a larger - amplitude wave. The number of wavelengths passing a point per second is frequency. The distance between crests and troughs is not relevant for compressional waves as they don't have crests and troughs in the same sense as transverse waves. Vibration of electric and magnetic parts is related to electromagnetic waves, not compressional waves.

Answer:

density of material in compressions and rarefactions