How is amplitude measured on a longitudinal wave?
The Correct Answer and Explanation is:
Correct Answer:
The amplitude of a longitudinal wave is measured by the maximum displacement of particles from their rest position, often represented by the degree of compression or rarefaction in the medium.
Explanation
In a longitudinal wave, particles of the medium move parallel to the direction of the wave’s travel. These waves consist of compressions, where particles are close together, and rarefactions, where particles are spread apart. Sound waves traveling through air are a common example of longitudinal waves.
Amplitude in a longitudinal wave refers to the maximum displacement of particles from their equilibrium (rest) position. This displacement determines the energy carried by the wave. The greater the displacement, the more energy the wave transports and the higher the amplitude.
To measure this amplitude, one observes how far the particles move during compressions and rarefactions. In practice, it is not always easy to measure the individual particle movement, especially in gases like air. Instead, amplitude is often inferred from measurable properties such as pressure variations. During compression, the air pressure is higher than normal, and during rarefaction, the pressure is lower. The greater the difference between these pressure extremes, the higher the amplitude of the wave.
In laboratory settings or simulations, amplitude can be visualized using graphs that show particle displacement or pressure changes over time or distance. The peak value of these graphs from the rest position represents the amplitude.
It is important to note that amplitude is not the distance between compressions or rarefactions; that measurement relates to the wavelength. Also, amplitude does not describe how fast the wave is moving; that is the wave speed. Instead, amplitude specifically describes the strength or intensity of the wave’s vibrations.
In sound waves, a higher amplitude results in a louder sound. In other contexts, such as seismic waves, greater amplitude corresponds to more ground movement and stronger tremors. Thus, amplitude plays a key role in determining a wave’s overall impact.
