Advertisements
Advertisements
Question
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?
Advertisements
Solution
Sound travels about 15 times faster in iron or steel than in air. We can hear the sound of an approaching train by putting our ear to the railway line made of iron or steel even when the train is far away because the sound produced by the motion of train’s wheels over the railway line is carried away quickly by the steel rails than in air.
APPEARS IN
RELATED QUESTIONS
Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen, why?
A boy on a hill A fires a gun. The other boy on hill B hears the sound after 4 s. If the speed of sound is 330 m s-1, find the distance between the two hills.
What name is given to those aircrafts which fly at speeds greater than the speed of sound?
A cricket ball is seen to hit the bat first and the sound of hitting is heard a little later. Why?
Explain why, the flash of a gun shot reaches us before the sound of the gun shot.
The speeds of sound in four different media are given below. Which of the following is the most likely speed in m/s with which the two under water whales in a sea talk to each other when separated by a large distance?
A man is kidnapped, blindfolded and imprisoned in a big room. How could the man tell if he was in : a city
Nita heard the sound of lightning after 4 seconds of seeing it. What was the distance of the lightning from her?
(The velocity of sound in air is 340 m/s.)
Numerical problem.
A stone is dropped from the top of a tower 750 m high into a pond of water at the base of the tower. Calculate the number of seconds for the splash to be heard? (Given g = 10 m s–2 and speed of sound = 340 m s–1)
Why does sound travel faster on a rainy day than on a dry day?
