An echo was heard after 3s. What is the distance of the reflecting surface from the source, given that the speed of sound is `342 ms^-1`?

What is the distance of the point (1, -2 , 3) from Z-axis ?

When a sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound production remains the same. Do you hear echo sound on a hotter day?

A man’stationed between two hills fires a gun. He hears the first echo after 1 s and the second after 2 s. What is the distance between the hills. The speed of sound in air is 330 m/s.

A SONAR (sound navigation and ranging) uses ultrasonic waves to detect and locate objects under water. In a submarine equipped with a SONAR the time delay between generation of a probe wave and the reception of its echo after reflection from an enemy submarine is found to be 77.0 s. What is the distance of the enemy submarine? (Speed of sound in water = 1450 m s^(-1) )

A tuning fork oscillates 350 times in second. What is the distance travelled by the sound wave emitted by the tuning fork after its 5 oscillation. The speed of sound in air is 350 m/s

A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top? Given, g= 10 m s^-1 and speed of sound = 340 m s^-1 .

A rain drop of radius 2 mm falls from a height of 500 m above the ground. It falls with decreasing acceleration (due to viscous resistance of the air) until at half its original height, it attains its maximum (terminal) speed, and moves with uniform speed thereafter. What is the work done by the gravitational force on the drop in the first and second half of its journey? What is the work done by the resistive force in the entire journey if its speed on reaching the ground is 10 m s-^1 ?

A source of sound is movig with a speed 220 m(s)^-1 towards a stationary target.While moving,it emits a wave of frequency 1000 Hz.Some of the sound reaching the target get reflected back to the source as echo.Calculate the (i)frequency of sound as detected by the target and (ii)the frequency of echo as detected by the source?

The escape speed of a projectile on the earth’s surface is 11.2 km s^-1 A body is projected out with thrice this speed. What is the speed of the body far away from the earth? Ignore the presence of the sun and other planets.

Light from a point source in air falls on a convex spherical glass surface ( refractive index = 1.5, radius of curvature = 20 cm). The distance of light source from the glass surface is 100 cm. At what position is the image formed ?