Advertisements
Advertisements
प्रश्न
The drawing shows a ship 800 m from a cliff. A gun is fixed on the ship. After 5 seconds the people at the front of the ship hear the sound of the gun again.
(a) What is the name of this effect ?
(b) What happens to the sound at the cliff ?
(c) How far does the sound travel in 5 seconds ?
(d) Calculate the speed of sound.
Advertisements
उत्तर
(a)The name of this effect is echo.
(b) Sound gets reflected back after reflecting from the cliff.
(c) Distance covered by sound wave in 5 s can be calculated as follows:
Incident sound travels distance (dI) = 800 m
Sound after reflection travels (dR) = 800 m
Total distance travelled by sound
= dI + dR
= (800 + 800) m
= 1600 m
(d) We have to calculate the speed of sound.
Given: Distance of cliff d = 800 m
Time taken to listen to the echo t = 5 s
So , time taken to reach the cliff `(t_1) = 5/2` s
So , speed of sound is
= `d/t_1`
= `(800 xx 2)/5` m/s
= 320 m/s
APPEARS IN
संबंधित प्रश्न
In which of the three media, air, water or iron, does sound travel the fastest at a particular temperature?
Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen, why?
A sound wave travels at a speed of 339 m s−1. If its wavelength is 1.5 cm, what is the frequency of the wave? Will it be audible?
What is meant by supersonic speed?
When we put our ear to a railway line, we can hear the sound of an approaching train even when the train is far off but its sound cannot be heard through the air. Why?
Hydrogen gas is filled in two identical bottles, A and B, at the same temperature. The mass of hydrogen in the two bottles is 12 gm and 48 gm respectively. In which bottle will sound travel faster? How many times be as fast as the other?
Write the formula for speed of sound in a gas using Laplace correction.
The speed of sound in a gaseous medium depends on ______.
Assertion: The speed of sound in air is less than the speed of sound in solid.
Reason: If we increase the temperature of medium, the speed of sound increases in any medium.
Numerical problems:
Two persons are at opposite ends of a steel rod. One strikes the end of the rod with a stone. Find the ratio of time taken by the sound wave in the air and in steel to reach the second person. (Sound of speed in steel = 5960 ms-1, Sound of speed in air = 344 ms-1).
