Reflection of Waves: Understanding Wave Behavior

by Yuvi K - December 18, 2023

Wave Reflection: Understanding Wave Behavior in Physics

Have you ever watched calm water in a pool ripple due to the presence of little pebbles? Have you ever put a spoon in a bowl of water and watched how the waves move? If you have, you have seen a phenomenon that happens in physics every day: wave reflection.

This article is about the physics behind wave reflection. We will discuss the different types of waves that have the capacity to reflect, as well as conditions under which they reflect back. We will also explain what exactly is happening inside the particles when a wave reflects, and we will highlight practical applications that rely upon wave reflection. So read on to learn about wave reflection!

What is Wave Reflection?

Wave reflection is a concept in physics that takes place when waves bounce off a certain medium and return in the same direction from which they came. This phenomenon of a wave bouncing off a surface and reflecting back is known as wave reflection.

The type of wave most usually associated with reflection is light. We can clearly see light reflecting off of mirrors, and even bouncing off of pullished surfaces. However, other types of waves can also exhibit wave reflection, such as sound waves and seismic waves. In fact, wave reflection is a phenomenon that can happen with waves of any type.

How Does Wave Reflection Work?

Wave reflection works due to the fact that different types of waves have different interactions with the mediums they encounter. When a wave encounters a medium, the particles of that medium tend to move according to the type of wave.

For instance, light waves, also known as electromagnetic waves, cause the particles in the medium they encounter to move in a backwards and forwards motion. On the other hand, sound waves cause the particles in the medium they encounter to move in a circular motion.

The type of movement demonstrated by the particles in the medium determines how the wave reflects. If the particles in the medium start to move forwards and backwards due to light, then the waves will reflect back in the same direction from which they came.

Conditions Required For Wave Reflection to Occur

For wave reflection to occur, two conditions must be met. Firstly, the medium that the wave is reflecting off of must be more rigid than the medium the wave is travelling through.

For instance, when light from the sun is reflected off of a mirror, not only does the mirror have to be more rigid than the air, but it also has to be polished to be able to reflect the light. If the surface is rough, the light will become scattered instead of reflected.

Secondly, the angle at which incident wave meets the reflecting medium must be greater than the angle at which the medium reflects back the wave. (This angle is known as the angle of reflection or angle of incidence in Hindi.) For instance, consider when a car passes by a wall and the sound waves the car produces encounter the wall. If you stand close enough you will hear a noise that is twice as loud as the original noise the car produced.

This is because the angle of incidence is greater than the angle of reflection, allowing the sound waves to reflect off of the wall and magnify.

What’s Happening Inside the Particles?

Everything that happens with wave reflection comes down to the particles inside the medium. Depending on the type of wave, these particles can move in a forwards and backwards (for light) or in a in a circular motion (for sound).

When the wave meets the medium and causes the particles to start moving, the energy of the wave is transferred to the particles in the medium via electromagnetic or sound vibrations. This in turn causes the particles to move in the direction determined by the type of wave and as a result, the wave reflects back in the same direction.

Applications of Wave Reflection

Wave reflection has a wide variety of applications, some of which are listed below:

• Radar: Radar works by emitting radio waves and then measuring the amount of time it takes for them to reflect back from a distant object. This time can be used to determine the distance and speed of the object.
• Medical imaging: Medical imaging techniques such as ultrasound and MRI make use of wave reflection to create an image of the body from the inside. The waves emitted by the scanner are reflected from the body, allowing the scanner to create an image.
• Sonar: Sonar works by sending sound waves into the ocean and then measuring the amount of time it takes for them to reflect back from a distant object. This time can be used to determine the distance and speed of the object.
• Communication: Reflection of RF (Radio Frequency) and microwave signals are typically used for the purpose of communicating data such as emails and text messages from one point to another (e.g. LTE signals).

Conclusion

Wave reflection is a phenomenon that occurs when waves encounter a medium and are reflected off of it. Different types of waves have different interactions with the mediums they encounter and the type of movement demonstrated by the particles in the medium determines how the wave reflects.

There are conditions required for wave reflection to occur, such as certain angle of incidence and rigidness of the medium. Furthermore, wave reflection has a variety of practical applications such as radar, medical imaging, sonar and communication.