Intensity

Definition

Intensity is the power per unit area carried by a wave, typically measured in watts per square meter ($W/m^2$). It quantifies the energy flow through a given surface area perpendicular to the direction of wave propagation.

5 Must Know Facts For Your Next Test

1. Intensity is proportional to the square of the amplitude of the wave.
2. In sound waves, intensity determines the loudness perceived by human ears.
3. For electromagnetic waves, intensity is related to both electric and magnetic fields.
4. The inverse square law states that intensity decreases with the square of the distance from the source.
5. Sound intensity level is measured in decibels (dB), calculated using a logarithmic scale.

Review Questions

• How does intensity relate to the amplitude of a wave?
• What unit is used to measure sound intensity level?
• Explain how intensity changes with distance from a point source according to the inverse square law.

Related terms

Amplitude:

The maximum displacement of points on a wave, which influences its energy and intensity.

Decibel (dB): A logarithmic unit used to express sound intensity level relative to a reference value.

Inverse Square Law:

A principle stating that intensity decreases proportionally with the square of the distance from the source.