Grade 8 Science Notes: Sound
Sound is a form of energy produced by vibrating objects and travels in waves.
--Characteristics of Sound:
1. Frequency:
- The number of vibrations per second, measured in Hertz (Hz).
- Determines the pitch of the sound.
2. Amplitude:
- The height of the sound wave.
- Determines loudness (higher amplitude = louder sound).
3. Speed:
- The rate at which sound travels.
- Fastest in solids, slower in liquids, and slowest in gases.
--Reflection of Sound:
- Echo: Sound waves bounce back from a surface.
- Example: Hearing echoes in a large hall.
--Applications of Sound:
- Communication (e.g., telephones, speech).
- Medical (e.g., ultrasound imaging).
- Technology (e.g., sonar for navigation).
--Importance of Sound:
- Essential for communication and music.
- Plays a crucial role in technology and science.