Available Answers

1. 1.

   A bat can hear sound of frequencies up io 120 kHz. Determine the minimum wavelength of sound which it can hear. Take speed or sound in air to be 344 m s^-1.

2. 2.

   Ocean waves of time period 10 s have wave velocity 15 m s^-1. Find : (i) the wavelength of these waves, (ii) the horizontal distance between a wave crest and its adjoining wave trough.

3. 3.

   A wave pulse of frequency 200 Hz, on a string moves a distance 8 m in s. Calculate : (a) the velocity or pulse, and (b) the wavelength of wave on string.

4. 4.

   Compare approximately the speed of sound in air and steel.

5. 5.

   The smoke from the gun barrel is seen 2 second before the explosion is heard. If the speed of sound in air is 340 m s-¹, calculate the distance of observer from gun. State the approximation used.

6. 6.

   The speed of sound in air is 330 m s^-1 and in water is 1650 m s^-1. It takes 2 s for sound to reach certain distance from the source placed in air. (a) Find the distance. (b) How much will it take for sound to reach same distance when the source is in water?