Sound
Core concepts and learning points for this section:
Syllabus Points
Core
- 3.4.1 Describe the production of sound by vibrating sources
- 3.4.2 Describe the longitudinal nature of sound waves
- 3.4.3 State the approximate range of frequencies audible to humans as 20 Hz to 20 000 Hz
- 3.4.4 Know that a medium is needed to transmit sound waves
- 3.4.5 Know that the speed of sound in air is approximately 330–350 m / s
- 3.4.6 Describe a method involving a measurement of distance and time for determining the speed of sound in air
- 3.4.7 Describe how changes in amplitude and frequency affect the loudness and pitch of sound waves
- 3.4.8 Describe an echo as the reflection of sound waves
- 3.4.9 Define ultrasound as sound with a frequency higher than 20 kHz
Supplement
- 3.4.10 Describe compression and rarefaction
- 3.4.11 Know that, in general, sound travels faster in solids than in liquids and faster in liquids than in gases continued www.cambridgeinternational.org/igcse 26 Subject content
- 3.4.12 Describe the uses of ultrasound in non- destructive testing of materials, medical scanning of soft tissue and sonar including calculation of depth or distance from time and wave speed