Page 14 - Final Science BB Prep2 Part one (2nd term) 2024-2025_Neat

v
Science Prep.2

Unit 2: Sound and Light

The Wave Nature of Sound:
-Sound is an external stimulus that affects the ear and causes hearing.

-Sound is produced by the vibrations of bodies.

G.R: We hear sound from all directions that surround the sound

Bec. Sound travels in air in the form of compression and rare faction

-Sound waves are mechanical longitudinal waves that propagate in different media in

the form of spheres where the source of sound is the center of the sphere.

-Sound Velocity:
I It is the distance covered by sound waves in one second.

V= Distance/time or V= F X λ

-Sound velocity in air is 340 meters / second.

-The velocity of sound in solids > in liquids > in gases

Sound heard by the human ear is classified into two types:

P.O.C Musical tones Noise

1-Frequency Uniform frequency Non-uniform frequency

2-Effect on the ear Comfortable uncomfortable

tuning fork- violin-piano hammering-loud speakers

3-Source

24