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. Greater density differences in compressions and rarefactions mean a larger - amplitude wave. The number of wavelengths passing a point per second is frequency. Compressional waves don't have crests and troughs like transverse waves. Vibration of electric and magnetic parts is related to electromagnetic waves, not compressional waves.

Answer:

density of material in compressions and rarefactions