Sound Waves

One of the many types of waves is sound. A sound Wave is one of the many waves that are mechanical which means its particles need to be connected to transfer its energy. Sound Waves can go through many types of solids, liquids and gases. Sound Waves can also be heard form the human ear if its within range. Many things can produce sound waves such as instruments, our voices and objects making physical contact with something.

An Example of a Sound Wave

Megaphones can create sound waves.

Doppler Affect

The Doppler Affect is the change of frequency in sound waves. It is usually noticed by a force that is moving toward the sounds. The doppler Affect was named after an Austrian physicist named Christian Doppler. He came up with the theory that sound waves would be different if a force was going near it. An example of the doppler affect would be a siren on a car moving to the right. The siren is producing the sound waves which is moving to different forces therefore creating the doppler affect. The Doppler Affect is used everywhere to Radars to track forces and to helping with blood measure and producing medical images. With out even noticing, the Doppler Affect is used in every day life.

Speed of Sound

The speed of sound is the distance travelled by sound waves in an amount of time. There are different speeds of sound due to different types of conditions. Different types of factors contribute to this such as the moisture in the air and ground, liquids going through our atmosphere, dry or cold air and gases going through our atmosphere. Listed below are the speed of sounds in different conditions.

Dry Air: 331.5 meters per second

Sea Level: 340.29 meters per second

As you can see from the results above, there are different speeds for different conditions. Depending on how loud the sound is, sound can travel at a fast rate. Temperature and density are big factors and can alter the results. Sound travels faster in sea level because it has more density and air has less.

A jet demonstrating the speed of sound

Vibration and Pitch


Vibration is caused by sound which causes an object to struck. When an object vibrates, the object pulls air molecules to the object. An example of vibration is a subwoofer getting music transferred to it therefore creating the subwoofer to vibrate. Vibration produces pressure waves which can travel through gases, solids and liquids. Vibrations can cause pitches which is explained below.


One of the things vibration can cause is pitch. Pitch is a usually a "high" or "low" sound. An example of a pitch is a pick going along a string on a guitar which can cause a low or high pitch. Pitch is often used in music to study songs, sounds and melodies. Vibration and pitch are very similar as they both cause sound waves and one of them causes the other.


Sound Waves can create echoes which which is basically a sound that repeats itself but slightly differently. If sound waves are going through a small, compacted area, this can creates echoes. For example if you yell in a cave, your yell will be repeated but in a slightly different tone. This echo happens because when the sound waves are released, they will travel to a nearby wall and will reflect right back where it came from. If the sound is approximately 17 meters away from a wall, it only takes 0.1 seconds to reflect back.


Resonance is a type of sound wave that is usually deeper or larger than others. Resonance can occur when vibration happens. For example, a speaker can produce resonance waves as it vibrates. Resonance is just one of the many sound waves.

Sound and Light waves

Sound and light waves have different properties to each other. They also behave in different waves. Here is the comparison below.

Sound Waves

Sound waves have three main different properties. The properties are wavelength, amplitude and frequency.


Wavelength is the distance the wave travels or the actual length of the wave. Most waves have wavelength as one of their properties.


Amplitude is the height of the wave or the power of the signal of the wave. Unlike wavelength, amplitude actually measures the height, not the distance. Most waves have amplitude as one of their properties.


Frequency is the number of times a wave travels every second. The faster the source of the wave vibrates, the higher the frequency is going to be. The vibration causes the pitch therefore making the wave have frequency. Most waves have frequency as one of their properties.

Light Waves

Light waves have different properties to what sound waves have. The main properties of light waves are wavelength, reflection, refraction and dispersion.


Referring to what was explained earlier, wavelength measures the distance of the wave travels.


Reflection is the light of the wave reflecting off a certain surface. An example of reflection is light reflecting off a surface like glass. Only light waves have reflection as one of their properties.


Refraction is the light of the wave bending pass substances and materials such as solids. Only Light waves have refraction as one of their properties.


Dispersion is when light waves have different frequency's therefore producing different colours of light. An example of dispersion is a rainbow. A rainbow is created by the frequency of the light wave which then creates the light colours.

Comparison of Sound and Light

Sound and light waves behave differently and have different properties to each other. Sound waves generally produce sound and light waves generally produce light and colours. They also have different properties to and thats why they behave in different ways.