In SONAR, we use (a) ultrasonic waves

Sound waves are called mechanical waves because it requires material medium to propagate. Sound is produced by the vibration of objects. When objects vibrate, it collides with the molecules in the...

t = 1.02 s, v = 1531 m/s  distance d = v × t = 1531×1.022 m = 780.81 m

Sound waves are called mechanical waves because they need a material medium to travel.

Infrasonic sound has frequency less than 20 Hz and ultrasonic sound has frequency higher than 20 kHz. 

SONAR is SOund Navigation And Ranging. It is a technique used to measure the depth of the sea, locate the sunken ships or icebergs and submarines.

Ultrasonic waves are those waves which have frequency more than 20 kHz.  Bats use ultrasonic waves to fly and search for their prey at night without colliding.  Bat produces ultrasound waves in...

Let the distance between the ship and the enemy submarine be ‘S’. Speed of sound in water = 1450 m/s Time lag between transmission and reception of Sonar waves = 77 s In...

The correct answer is (a) A EXPLANATION:   The resultant amplitude   y = A sin(⍵t-kx) + A sin(⍵t-kx+120°)    →y = 2A Sin(⍵t-kx+60°)*cos60°    →y = A sin(⍵t-kx+60°)      Hence the resultant amplitude is A.

The correct answer is (a) P1= P2   EXPLANATION:  Let the cross-section area = A, if the intensity of the first wave at this cross-section = I₁ and of the second wave =...

(a) longitudinal stationary waves EXPLANATION:  An organ pipe open at both ends contains sound waves which are longitudinal waves, so the option (c) and (d) are not true. When the waves enter...