"SONAR is used to find the distance of an object in the sea and RADAR is mainly used for air and ground traffic". Mention three other differences between them.
Sound travels at a speed of through water. A submarine detects objects around it by sending sound waves and detecting echo (reflected sound) heard after . Then the object must be at a distance of:
A girl drops a ball from a height . It strikes the ground elastically and returns to her hand. An echo of the thud of the ball striking the ground is produced from a nearby cliff. The echo is head at exactly the same moment when the ball returns to the girl's hand. (Take g = and ). The distance of the cliff from the girls is close to:
A man who is standing at a distance of from a sound reflecting surface claps loudly. If the velocity of the sound in air is then the time taken by the echo to reach him is
Sound signal from a ship floating in water hits the bottom of the sea and reflects back to the ship after . Speed of sound in water is . Calculate the depth of the sea.
A man standing in front of a vertical cliff fires a gun. He hears the echo after . On moving closer to the cliff by , he hears the echo after . Calculate the distance of the cliff from the initial position of the man.
A pendulum has a frequency of vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from the cliff after vibrations of the pendulum. If the velocity of sound in air is , find the distance between the cliff and the observer.
An observer standing between two cliffs hears two successive echoes at and respectively. Calculate the distance between the cliffs. (speed of sound in air ).
