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Shaalaa.com | Numerical
A man fires a gun and hears its echo after 5 s. The man then moves 310 m towards the hill and fires his gun again. This time he hears the echo after 3 s. calculate the speed of sound.
A man standing 48 m away from a wall fires a gun calculate the time after which an echo is heard. (The speed of sound in air is 320 m s -1).
A radar sends a signal to an aeroplane at a distance 45 km away with a speed of 3 × 108 m s -1. After how much time is the signal received back from the aeroplane?
A pendulum has a frequency of 4 vibrations per second. An oberver starts the pendulum and fires a gun simultaneously. He hears the echo from the cliff after 6 vibrations of the pendulum, if the velocity of sound in air is 340 m/s, find the distance betwen the cliff and the obsever.
A ship on the surface of water sends a signal and receives it back froma a submarine inside water after 4 s. Calculate the distance of the submarine from the ship. (The speed of sound in water is 1450 m s-1)
On sending an ultrasonic wave from a ship towards the bottom of a sea, the time interval between sending the wave and receiving it back is found to be 1.5 s. If the velocity of wave in sea water is 1400 m s-1, find the depth of the sea.
What should be the minimum distance between source and reflector in water so that echo is heard distinctly?
(The speed of sound in water = 1400 m s-1)