Question

1. how does sound intensity differ from loudness?

loudness is measured in hertz, and intensity is measured in decibels.
intensity is measured in hertz, and loudness is measured in decibels
intensity is a universal measurement, and loudness varies from person to person.
loudness is a universal measurement, and intensity varies from person to person.

Explanation:

Sound intensity is the power per unit area carried by a sound wave, a physical quantity with a universal measurement. Loudness is a subjective perception of how strong a sound seems to an individual and varies from person to person. Hertz measures frequency, not loudness or intensity, and decibels can measure both intensity - level and loudness - level but the key difference is the objectivity of intensity and subjectivity of loudness.

Answer:

C. Intensity is a universal measurement, and loudness varies from person to person.