Lesson Notes By Weeks and Term v4 - SHS 2
WAVES
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WAVES
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Subject: Physics
Class: SHS 2
Term: 1st Term
Week: 20
Grade code: 2.2.2.LI.2
Strand code: 2
Sub-strand code: 2
Content standard code: 2.2.2.CS.2
Indicator code: 2.2.2.LI.2
Theme: ENERGY
Subtheme: WAVES
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Sound is an integral part of our daily lives in Ghana. From the vibrant rhythms of Highlife music and the call to prayer, to the bustling noise of Makola Market and the quiet hum of a fan at night, we are surrounded by sound. However, the world of sound is much wider than what our ears can perceive. There are sounds so low in pitch that only animals like elephants can hear them, and sounds so high that they are used by bats to navigate and by doctors to see inside the human body. This lesson explores the classification of sound based on its frequency.
A. Recap: What is Sound and Frequency? Sound: Sound is a form of energy that travels as a longitudinal wave through a medium (like air, water, or solids). It is produced by vibrating objects. Frequency (f): Frequency is the number of complete vibrations or cycles a wave makes in one second. It determines the pitch of a sound. A high frequency means a high pitch (like a whistle), and a low frequency means a low pitch (like a deep drum). Unit of Frequency: The SI unit for frequency is the Hertz (Hz). 1 Hz = 1 vibration per second. 1 kilohertz (kHz) = 1,000 Hz. 1 megahertz (MHz) = 1,000,000 Hz. B. The Spectrum of Sound Frequencies
The human ear is a remarkable organ, but it can only detect sound waves within a specific range of frequencies. We can classify all sound waves into three main categories based on whether they fall below, within, or above this range.
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INFRASONIC AUDIO-SONIC (AUDIBLE) ULTRASONIC (Infrasound) (Human Hearing) (Ultrasound)