Sound Waves Basics

IGCSE Edexcel Physics
3.2, 3.23 Sound Waves
Key Concepts: Sound waves are longitudinal and can be reflected and refracted.

Section A: Properties

1. State whether sound waves are longitudinal or transverse. [1]
2. Explain how sound can be reflected to produce an echo. [2]
3. Describe how sound can be refracted. [2]

Section B: Calculation

4. A sound wave has frequency 170 Hz and speed $340\,m/s$. Calculate wavelength. [2]
Total marks: 7

Mark Scheme

1. Longitudinal [1]
2. Sound reflects from a surface and returns to the listener [2]
3. Refraction occurs when speed changes in different air layers [2]
4. $\lambda = v/f = 340/170 = 2\,m$ [2]