What is the process by which a wave changes direction and travels back after hitting a surface?
The process by which a wave changes direction and travels back after hitting a surface is called wave reflection. When a wave encounters a boundary or an obstacle, such as a wall or a mirror, a portion of the wave energy bounces back into the original medium. This process occurs for various types of waves, including sound waves, light waves, and water waves.
To understand the process of wave reflection, you can follow these steps:
1. Wave propagation: Initially, a wave is traveling through a medium, such as air, water, or a solid. The wave consists of oscillations or disturbances in the medium, which carry energy with them.
2. Encounter with a boundary: As the wave reaches a boundary, it comes into contact with a different medium or surface. The properties of the boundary determine how the wave will behave upon reflection.
3. Incident wave: The portion of the wave that arrives at the boundary is called the incident wave. It approaches the boundary at a certain angle, known as the angle of incidence. This angle is measured between the direction of the incident wave and the normal line— a line perpendicular to the boundary surface.
4. Reflection: Upon reaching the boundary, a part of the wave energy is reflected back into the original medium. This portion is known as the reflected wave. The angle between the direction of the reflected wave and the normal line is called the angle of reflection. According to the law of reflection, the angle of incidence is equal to the angle of reflection.
5. Reflected wave: The reflected wave travels in the opposite direction to the incident wave. It carries the wave energy back through the medium.
It's important to note that the remaining fraction of the incident wave can be transmitted into the new medium, causing the wave to continue propagating in a different direction.
Understanding the concept of wave reflection helps explain various phenomena, such as how we see ourselves in a mirror, how echoes are formed, and how sound is reflected in concert halls.