
Subscribe to our Youtube Channel - https://you.tube/teachoo
Last updated at June 26, 2019 by Teachoo
Transcript
NCERT Question 7 A person has a hearing range from 20 Hz to 20 kHz. What are the typical wavelengths of sound waves in air corresponding to these two frequencies? Take the speed of sound in air as 344 m s–1. Hearing range for humans = 20 Hz to 20 kHz = 20 Hz to 20,000 Hz Speed to sound = v = 344 m/s We know that, Speed of sound = Wavelength × Frequency Wavelength = (𝑆𝑝𝑒𝑒𝑑 𝑜𝑓 𝑠𝑜𝑢𝑛𝑑)/𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 Frequency = 20 Hz Wavelength = (𝑆𝑝𝑒𝑒𝑑 𝑜𝑓 𝑠𝑜𝑢𝑛𝑑)/𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 = 344/20 = 172/10 = 17.2 m Frequency = 20,000 Hz Wavelength = (𝑆𝑝𝑒𝑒𝑑 𝑜𝑓 𝑠𝑜𝑢𝑛𝑑)/𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 = 344/20000 = 172/10000 = 0.0172 m Wavelength of frequency 20 Hz is 17.2 m Wavelength of frequency 20000 Hz is 0.0172 m
NCERT Questions
NCERT Question 2
NCERT Question 3
NCERT Question 4
NCERT Question 5
NCERT Question 6
NCERT Question 7 You are here
NCERT Question 8
NCERT Question 9
NCERT Question 10
NCERT Question 11
NCERT Question 12
NCERT Question 13
NCERT Question 14
NCERT Question 15
NCERT Question 16
NCERT Question 17
NCERT Question 18
NCERT Question 19
NCERT Question 20
NCERT Question 21
NCERT Question 22
About the Author