Question

Why does police use dogs for detective work?
A. Because they have sharp eyesight
B. Because they can hear ultrasonic waves
C. Because they can identify objects by smell
D. All of these

Answer 1

Hint:We know that the frequency less than 20Hz is infrasonic, frequency greater than 20,000Hz is ultrasonic; 20Hz to 20,000Hz is the audible range for the human ear. Humans, animals, and birds can hear sound with different frequencies.

Complete step by step answer:
The Frequency above 20,000Hz is ultrasonic range. The audible range of dogs, cats is ultrasound frequencies. They can hear high frequencies that humans cannot. The human audible range is 20Hz to 20,000Hz; humans can't hear above frequencies. Also, the infrasonic is less than 20Hz, which is rarely audible to human hearing. The human ear is sensitive due to pressure difference in the air if they are in the audible frequency range. But dogs, cats, bats, and lions have sharp eyesight and smell or hear the ultrasonic waves.

Therefore the correct option is (D).

Note:Waves produced from material and need material for their propagation are mechanical waves, and sound is an example of such types of waves. When any object vibrates at a particular frequency, which ranges between 20Hz to 20,000Hz is called sonic waves or sound. The other waves are inaudible because the sensory organs are not adapted to hear such kinds of sound waves. Whales and elephants can hear infrasonic sound waves. Dogs, cats can extend their hearing capacity to the ultrasonic range. The human ear is comfortable with an audible range of 20Hz to 20,000Hz.