When a wave is reflected from an object, the behavior of its amplitude depends on the properties of the object and the nature of the wave. Let's consider a few scenarios:
Reflection from a fixed boundary: If a wave reflects from a fixed boundary, such as a rigid wall or a solid object, the amplitude of the wave remains the same after reflection. This is true for various types of waves, including sound waves, light waves, and water waves, assuming no energy is absorbed or lost during the reflection.
Reflection from a free boundary: In the case of a wave reflecting from a free boundary, such as an open end or a free end of a string, the amplitude of the reflected wave can be affected. The reflection from a free boundary can lead to wave interference, resulting in phenomena such as standing waves. The specific changes in amplitude depend on factors such as the properties of the wave and the boundary conditions.
Reflection with impedance mismatch: In some cases, when a wave encounters a boundary with a different impedance (a measure of the resistance to wave propagation), the amplitude of the reflected wave may be modified. For example, when a sound wave reflects from a surface with a different acoustic impedance, such as the transition from air to water, a portion of the energy may be transmitted while another portion is reflected, causing a change in the amplitude of the reflected wave.
It's important to note that the above scenarios provide general insights, but the behavior of reflected waves can be quite complex and is often subject to specific conditions and properties of the wave and the reflecting medium. The study of wave reflection is a fundamental aspect of wave physics and can be further explored within the context of specific wave phenomena and systems.