JSS 2: Sound energy (II)

The speed of sound is the distance traveled per unit of time by a sound wave as it passes through a material medium. The speed of sound depends on the type of medium in which the sound propagates. The speed of sound in air is about 330m/s. 

Speed of sound =Frequency x wavelength 

                          V= f x λ

Example 1: What is the wavelength of the sound from a tuning fork that vibrates at a frequency of 300Hz in air? (velocity of sound = 330m/s)

Solution:

Speed of sound =Frequency x wavelength 

                          V= f x λ

                     330 = 300 x λ

                         λ = 330/300 

                         λ = 1.1 m 

Example 2: A source of sound produces waves in air of wavelength 1.5m. If the speed of sound in air is 330m/s. Find the frequency of the vibration 

Solution:

Speed of sound =Frequency x wavelength 

                          V= f x λ

                     330 = f x 1.5 

                          f = 330/1.5 

                          f = 220Hz 

                Musical instruments 

Musical instruments are instruments created to produce musical sounds.

Musical instruments are classified into:

1. Wind instruments

2. Stringed instruments

3. Percussion instruments 

                  Wind instruments 

These are instruments that produce sound through a vibrating column of air.

E.g. Flutes, trumpets, pipe organs, clarinets, saxophones, etc 

                  Stringed instruments 

These are musical instruments that produce sound when the strings are struck.

E.g. Guitars, sonometers, pianos, violins, etc 

                  Percussion instruments 

These are musical instruments that produce sound when it is hit or struck.

E.g. Talking drums, bells, gongs, xylophone, tuning fork, cymbals, etc

                      Musical instruments