2 What have I learned about sound?

Summary: Tags: science oxford-science student-book-7 physics Created: 2026-05-19 Last Updated: 2026-05-19

In this chapter, you have:

• learned about Sound wave properties – waves have a wavelength, a frequency, and an amplitude, and they travel at different speeds
• understood that vibrating objects produce sound, which travels fastest in solids because the particles are closer together
• learned that sound cannot travel through a vacuum
• studied how the ear detects sound to produce a signal that is sent to the brain, and that a microphone does a similar thing
• discovered how we can use echoes to measure distance and to produce ultrasound images
• learned that we can use sound for lots of different things, from playing instruments and listening to music, to looking inside the human body and treating patients in hospital.

Journey through sound What do I already know? - Sound vibrations

• Pitch and volume This chapter - 2.1 Waves
• 2.2 Sound
• 2.3 Loudness and pitch
• 2.4 Detecting sound
• 2.5 Echoes and ultrasound What comes next? - Wave properties
• Sound and its applications
• Energy stores and energy transfers

Table 1

1. Circle the words that can be used to describe waves oscillatingbalancingvibratingrepelling (2 marks)Complete the sentences with the words. wavelengthfrequencyamplitude The distance from the middle to the top of a wave is the blank. The distance from one trough to the next trough is the blank. The number of waves per second is the blank. (3 marks)
2. A sound wave travels through water and bounces off the sea floor. Choose the correct words. The sound wave is attached to/reflected by the sea floor. (1 mark)The sound wave travels faster/slower in air than it does in water. (1 mark)
3. A tuning fork produces this wave on an oscilloscope. Figure 1 Draw the wave you would see if the sound were louder. (1 mark)Draw the wave you would see if the sound had a higher pitch. (1 mark)A note has a frequency of 400 Hz. State how many sound waves pass a point per second. (1 mark)
4. A friend calls your name. Describe: how the sound wave is produced (1 mark)how it travels to your ear (1 mark)how it produces a signal that reaches your brain. (4 marks)
5. Think about waves travelling through a medium. Describe how particles in a medium move when a longitudinal wave passes through it. (1 mark)Explain how your answer to a would change if a wave with a larger amplitude moved through the same medium. (1 mark)
6. Describe how a simple microphone works. (4 marks)
7. Table 1 shows the Speed of sound in three different materials: A, B, and C. Table 1Material Speed in m/s A 1250 B 300 C 5000 Write down which material is probably a solid. (1 mark)Write down which material is probably a gas. (1 mark)Suggest a reason why the three speeds are different. (1 mark)
8. Write down which of the frequencies are ultrasound. (1 mark) 2000 Hz25 kHz300 Hz1000 kHz100 000 HzSuggest how dolphins use ultrasound to detect fish. (2 marks)Explain why dolphins can communicate using sound across much larger distances than a human can. (2 marks)
9. The speed of sound in water is 1500 m/s. The depth of a sea is 4500 m. A ship sends down an ultrasound signal. Calculate how long it takes to detect the echo. Hint: first, work out the total distance that the sound travels. Then divide this by the speed of sound in water to get the time taken. (4 marks)