. A person standing near the cliff fires the gun and heared the echo after 1.5 sec . If the speed of sound in air is 340m/sec , how far is person from the cliff? 

3. A sound wave of frequency 5000 Hz travel in air with speed of 350m/sec. Calculatethe wave length. 

4. If u hear thunder 7 sec after u see yhe lightining , how far u from the lighting occurred? 

5. A bat emits ultrasonic wave of frequency 30 Khz..If its speed is 350m/s and bats hear its echo after 0.6 sec after emitting the , find how far is bat from obstacle and wave length of wave? 

6. Meera is standing between two hills.She shouted loudly and hears first echo after 0.5 sec and second echo after 1 sec. what is distance between two hills? 7. If 2000 ripples produced in 5 sec in a pond find time period and frequency of ripples formation. 

8. A man standing in a valley between two parallel mountains fires a gun and hears echo at an interval of 2 s and 3.5s. what is a) the distance between two mountains b) the location of the man with respect to the mountain.

  9. Calculate the wavelength of a sound whose frequency is 220 Hz and speed is 440 in a given medium.
  10. A body is vibrating 6000 times is 1 minute. If the velocity of sound in air is 360 m/s, find 
(i) Frequency in Hz   (ii) wavelength of sound. 
  11. . A stone is dropped from a 500 m tall building into a pond. When is sound splash heard? Given g=10 m/s2 , speed of sound = 340 m/s. 
  12. An echo is heard in 3 sec after the emission of sound. If speed of sound in air is 342 m/s, what is the distance of the reflecting surface from the source?