Check sibling questions
Class 9
Chapter 12 Class 9 - Sound

Slide1.JPG

Slide2.JPG
Slide3.JPG
Slide4.JPG
Slide5.JPG

Solve all your doubts with Teachoo Black (new monthly pack available now!)


Transcript

Example 12.1 A sound wave has a frequency of 2 kHz and wave length 35 cm. How long will it take to travel 1.5 km? Frequency of sound = f = 2 kHz = 2000 Hz Wavelength = πœ† = 35 cm = 35/100 m = 0.35 m Distance travelled = d = 1.5 km = 1.5 km Γ— 1000 = 15/10 Γ— 1000 = 1500 m We know that, Speed of sound = Wavelength Γ— Frequency v = πœ† Γ— f v = 0.35 Γ— 2000 v = 35/100 Γ— 2000 v = 700 m/s We know that, Speed = π·π‘–π‘ π‘‘π‘Žπ‘›π‘π‘’/π‘‡π‘–π‘šπ‘’ Time = π·π‘–π‘ π‘‘π‘Žπ‘›π‘π‘’/(𝑆𝑝𝑒𝑒𝑑 π‘œπ‘“ π‘ π‘œπ‘’π‘›π‘‘) = 1500/700 = 15/7 = 2.1 s Time taken by sound is 2.1 s

CA Maninder Singh's photo - Co-founder, Teachoo

Made by

CA Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 12 years and a teacher from the past 16 years. He teaches Science, Economics, Accounting and English at Teachoo