Example 12.1 - Chapter 12 Class 9 - Sound (Deleted)
Last updated at June 26, 2019 by Teachoo
Examples from NCERT Book
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 = 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 Γ f v = 0.35 Γ 2000 v = 35/100 Γ 2000 v = 700 m/s We know that, Speed = π·ππ π‘ππππ/ππππ Time = π·ππ π‘ππππ/(πππππ ππ π ππ’ππ) = 1500/700 = 15/7 = 2.1 s Time taken by sound is 2.1 s