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Lucía
27/11/2025
Physics
The Nature of Waves
196
•
27 Nov 2025
•
Understanding Waves: Physics GCSE Revision Notes
Lucía
@luttior
1 / 4
The Nature of Waves
Waves transfer energy while moving through different mediums. They come in many types including sound waves (allowing us to hear), radio waves (carrying information between devices), seismic waves (causing earthquakes), x-rays (passing through objects), and light waves (enabling sight).
There are two main wave types: transverse waves and longitudinal waves. In transverse waves, the vibration occurs perpendicular (at right angles) to the direction of travel - imagine a wave moving forward while the particles move up and down. Electromagnetic waves like x-rays and microwaves are transverse waves.
Longitudinal waves work differently - the particles move parallel to the direction of travel, creating areas of compression (where particles bunch together) and rarefaction (where they spread apart). Sound waves are a common example of longitudinal waves.
Remember this: Transverse waves move side-to-side (perpendicular), while longitudinal waves move back-and-forth (parallel) to the direction the wave is traveling.
Wave Properties and Measurements
Waves have several key properties you can measure. The amplitude is the wave height from the normal position to the peak, affecting loudness in sound waves. The wavelength is the distance between consecutive peaks (or troughs).
Pitch in sound is determined by frequency - low pitch sounds have fewer waves (low frequency), while high pitch sounds have more waves (high frequency). The difference between soft and loud sounds comes down to amplitude, not frequency.
Wave speed can be calculated using the equation: Wave speed = Frequency × Wavelength. The units are metres per second for speed, Hertz (Hz) for frequency, and metres (m) for wavelength. For example, if a wave has a frequency of 5 Hz and wavelength of 2 m, its speed would be 10 m/s.
Quick tip: Remember the wave equation as v = f × λ (where v is velocity, f is frequency, and λ is wavelength). This simple formula helps you calculate any one value if you know the other two.
The Electromagnetic Spectrum
The electromagnetic spectrum arranges waves by wavelength and frequency. Radio waves have the longest wavelength and lowest frequency, while gamma rays have the shortest wavelength and highest frequency.
Different parts of the spectrum have different uses and dangers. Radio waves are used for telecommunications (TV, radio) and are generally harmless. Microwaves are used for communications, radar and cooking, but can cause burns and other injuries. Infrared waves provide heat and are used in remote controls and night vision.
Visible light allows us to see but bright light can damage eyes. Ultraviolet (UV) light is used in discos and tanning salons but can cause skin cancer. X-rays help with medical imaging but carry cancer risks. Gamma rays treat cancer but are themselves dangerous, potentially causing cancer with exposure.
Fascinating fact: Every part of the electromagnetic spectrum is essentially the same type of energy - just at different frequencies. The only difference between radio waves and gamma rays is their wavelength and energy level!
Harmful Radiation and Applications
Ultraviolet light has useful applications in discos, tanning salons and even helping flowers with pollination. However, it's important to know that UV exposure carries significant risks, particularly skin cancer from overexposure.
X-rays revolutionised medicine by allowing doctors to see inside the body without surgery. They're also used in security screening at airports. Despite their benefits, x-rays are a form of ionising radiation that can damage cells and potentially lead to cancer, which is why exposure is strictly controlled.
Gamma rays are the most energetic form of electromagnetic radiation. They're used to treat cancer (ironically, by killing cancer cells) and help astronomers observe distant parts of the universe. Their high energy makes them extremely dangerous, requiring substantial shielding to protect people from exposure.
Safety note: The more energetic the radiation (as you move from radio waves toward gamma rays), the more potentially harmful it becomes to living tissue. That's why we need protection from UV, X-rays, and gamma rays, but not from radio waves.
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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
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This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
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Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Understanding Waves: Physics GCSE Revision Notes
Lucía
@luttior
Waves are vibrations that transfer energy from one place to another. They're all around us in different forms, from the sound we hear to the light that lets us see. Understanding waves helps explain how we experience much of our... Show more
The Nature of Waves
Waves transfer energy while moving through different mediums. They come in many types including sound waves (allowing us to hear), radio waves (carrying information between devices), seismic waves (causing earthquakes), x-rays (passing through objects), and light waves (enabling sight).
There are two main wave types: transverse waves and longitudinal waves. In transverse waves, the vibration occurs perpendicular (at right angles) to the direction of travel - imagine a wave moving forward while the particles move up and down. Electromagnetic waves like x-rays and microwaves are transverse waves.
Longitudinal waves work differently - the particles move parallel to the direction of travel, creating areas of compression (where particles bunch together) and rarefaction (where they spread apart). Sound waves are a common example of longitudinal waves.
Remember this: Transverse waves move side-to-side (perpendicular), while longitudinal waves move back-and-forth (parallel) to the direction the wave is traveling.
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Wave Properties and Measurements
Waves have several key properties you can measure. The amplitude is the wave height from the normal position to the peak, affecting loudness in sound waves. The wavelength is the distance between consecutive peaks (or troughs).
Pitch in sound is determined by frequency - low pitch sounds have fewer waves (low frequency), while high pitch sounds have more waves (high frequency). The difference between soft and loud sounds comes down to amplitude, not frequency.
Wave speed can be calculated using the equation: Wave speed = Frequency × Wavelength. The units are metres per second for speed, Hertz (Hz) for frequency, and metres (m) for wavelength. For example, if a wave has a frequency of 5 Hz and wavelength of 2 m, its speed would be 10 m/s.
Quick tip: Remember the wave equation as v = f × λ (where v is velocity, f is frequency, and λ is wavelength). This simple formula helps you calculate any one value if you know the other two.
Sign up to see the contentIt's free!
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Improve your grades
Join milions of students
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The Electromagnetic Spectrum
The electromagnetic spectrum arranges waves by wavelength and frequency. Radio waves have the longest wavelength and lowest frequency, while gamma rays have the shortest wavelength and highest frequency.
Different parts of the spectrum have different uses and dangers. Radio waves are used for telecommunications (TV, radio) and are generally harmless. Microwaves are used for communications, radar and cooking, but can cause burns and other injuries. Infrared waves provide heat and are used in remote controls and night vision.
Visible light allows us to see but bright light can damage eyes. Ultraviolet (UV) light is used in discos and tanning salons but can cause skin cancer. X-rays help with medical imaging but carry cancer risks. Gamma rays treat cancer but are themselves dangerous, potentially causing cancer with exposure.
Fascinating fact: Every part of the electromagnetic spectrum is essentially the same type of energy - just at different frequencies. The only difference between radio waves and gamma rays is their wavelength and energy level!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
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By signing up you accept Terms of Service and Privacy Policy
Harmful Radiation and Applications
Ultraviolet light has useful applications in discos, tanning salons and even helping flowers with pollination. However, it's important to know that UV exposure carries significant risks, particularly skin cancer from overexposure.
X-rays revolutionised medicine by allowing doctors to see inside the body without surgery. They're also used in security screening at airports. Despite their benefits, x-rays are a form of ionising radiation that can damage cells and potentially lead to cancer, which is why exposure is strictly controlled.
Gamma rays are the most energetic form of electromagnetic radiation. They're used to treat cancer (ironically, by killing cancer cells) and help astronomers observe distant parts of the universe. Their high energy makes them extremely dangerous, requiring substantial shielding to protect people from exposure.
Safety note: The more energetic the radiation (as you move from radio waves toward gamma rays), the more potentially harmful it becomes to living tissue. That's why we need protection from UV, X-rays, and gamma rays, but not from radio waves.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
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Is Knowunity really free of charge?
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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user