3.4 — Sound

Core

3.4.1 — Describe production of sound by vibrating sources
3.4.2 — Describe longitudinal nature of sound waves
3.4.3 — State frequency range of human hearing (20 Hz to 20 kHz)
3.4.4 — Know that a medium is required to transmit sound waves
3.4.5 — Know that speed of sound in air is approximately 330–350 m/s
3.4.6 — Describe method to determine speed of sound using distance/time measurement
3.4.7 — Describe how amplitude and frequency affect loudness and pitch
3.4.8 — Describe an echo as the reflection of sound waves
3.4.9 — Define ultrasound as sound with frequency above 20 kHz

3.4.10 — Describe compression and rarefaction in sound waves
3.4.11 — Know that sound travels faster in solids than liquids, and faster in liquids than gases
3.4.12 — Describe uses of ultrasound in NDT, medical scanning and sonar; calculate depth using time and speed