Advertisements
Advertisements
Question
How are bats able to fly in the dark?
Advertisements
Solution
Sound waves of frequency higher than 20,000 hertz are not audible to human ears. Those are known as ultrasonics. Let us explain how bats can avoid obstacles while flying in complete darkness. During the flight in complete darkness, a bat produces ultrasound in a series of impulses. The impulses on reflection from the obstacle under observation are received by the animal. The animal interprets the distance of the obstacle from the time interval between the transmission and reception of the impulses. The phase difference between the echoes received by the ears enables the animal to locate the exact position of the obstacle.
RELATED QUESTIONS
A wave passes from one medium to another medium. Mention one property of the wave out of speed, frequency or wavelength which changes.
What is a megaphone ? Name the principle on which a megaphone works.
Draw a labelled diagram to show the multiple reflections of sound in a part of the stethoscope tube.
Explain how the principle of echo is used by
The dolphin to locate small fish as its prey
Explain how is the principle of echo used by
(a) The bat during its flight at night,
(b) The dolphin to locate small fish as its prey.
What are infrasonic waves?
A cork piece is floating on the surface of the water in a pond. A piece of pebble is dropped into the water. What will be your observation?
A radio signal, sent towards the surface of the moon, is received in 2.5 seconds. If the speed of the radio waves is 3 × 108 ms−1, find the distance of the moon from the earth.
