Q1) Find the frequency of a wave whose time period is 0.002 second.

Q2)Find the time period of the source of a sound wave whose frequency is 400 Hz.

Q3) A sound wave causes the density of air at a place to oscillate 1200 times in 2 minutes. Find the time period and frequency of the wave aves?

Q4) A source produces 15 crests and 15 troughs in 3 seconds. When the second crest is produced, the first is 2 cm away from the source. Calculate (a) the wavelength, (b) the frequency, and (c) the wave speed.

Q5) A sound wave travels at a speed of 340 m/s. If its wavelength is 2 cm, what is the frequency of the wave? Will it be in the audible range?

Q6) Given that sound travels in air at 340 m/s, find the wavelength of the waves in air produced by a 20-kHz sound source. If the same source is put in a water tank, what would be the wavelength of the sound waves in water? Speed of sound in water 1480 m/s.

Q7) A child watching Dusserah celebrations from a distance sees the effigy of Ravana burst into flames and hears the explosion associated with it 2 s after that. How far was he from the effigy if the speed of sound in air that night was 335 m/s?

Q8) The war correspondent of a TV channel watches the flashes of two tanks firing at each other at the same time on a straight road ahead of him. He hears the sounds of the two shots 2 seconds and 3.5 seconds after seeing the flashes. Taking the speed of sound in air as 340 m/s, he quickly calculates and reports the distance between the tanks. What distance did he report?

Q9. A bat in search of prey hears the echo of its squeak after 0.1 s. How far is the prey from the bat, if the squeak got reflected from it? (Speed of sound in air 340 m/s.)

Q10) A fishing boat using sonar detects a school of fish 190 metres below it. How much time elapsed between sending the ultrasonic signal which detected the fish and receiving the signal's echo? Speed of sound in sea water=1,520 m/s.)

Q11. A monkey drops a coconut from the top of a tree. He hears the sound of the coconut hitting the ground 2.057 seconds after dropping it. If the monkey was 19.6 metres above the ground, what is the speed of sound in air? (Take g 9.8 m/s2)