Understanding the equation for a sound wave

From founding communications, such as the fire beacon, to being able to communicate with space, there is no denying that developments in communication have advanced at a rapid speed. This topic presents students with communications of the past, present and future, helping them to understand the principles that form the basis for these developments.

This engaging STEM activity is aimed at KS3 students and deals with how animals use sounds and how sounds change in natural phenomena. This is so that a student can understand how sound waves travel.

Activity: Understanding the equation for a sound wave

The teacher will first distribute a copy of the ‘Animal Sounds’ handout, which can be downloaded below, to each student.

Make sure students understand sound is a longitudinal wave of compressions and rarefactions of the material. Soundwaves follow the laws of wave behaviour, so they are a useful introduction to wave properties.

This activity can be simplified (particularly for less able students) by creating a discussion on why different animals have different hearing ranges and their experience of phenomena such as the Doppler effect.

Use the handout to discuss different sounds and what they might have learned in other lessons (e.g. music) about pitch, frequency, amplitude etc.

As an extension students could produce a display from low to high frequency, showing where the sound ranges used by different animals lie. Students could consider how sounds outside the normal spectrum could be used to develop new products. For example, to make ‘silent’ devices to broadcast sound or data between two points.

This is a quick and simple activity that will take approximately 15 minutes.

Tools/resources required

• Calculators

The engineering context

Sounds are vibrations travelling through materials. Many animals make sounds, either for communication or for location. Sound travels at different speeds in different materials. Generally, the denser the material, the faster the sound will travel.

Sound is a longitudinal wave of compressions and rarefactions of the material (a rarefaction involves particles in the material being more spread out than usual). Sound waves follow the laws of wave behaviour, so they are a useful introduction to wave properties.

Suggested learning outcomes

By the end of this free resource students will know that sound is produced by objects vibrating and they will understand that sound is a longitudinal wave. They will also know about the range of frequencies that can be heard by humans and other animals and they will understand that sound travels at different speeds in different mediums.

Download the free Understanding the equation for a sound wave activity sheet below!

All activity sheets and supporting resources are free to download, and all the documents are fully editable, so you can tailor them to your students’ and your schools’ needs.

The activity sheet includes teacher notes, guidance, useful web links, and links (where appropriate) to the national curriculum in each of the four devolved UK nations; England, Northern Ireland, Scotland and Wales.

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