Advertisements
Advertisements
प्रश्न
A source of sound is travelling with a velocity 40 km/h towards an observer and emits a sound of frequency 2000 Hz. If the velocity of sound is 1220 km/h, then the apparent frequency heard by the observer is _____.
Advertisements
उत्तर
A source of sound is travelling with a velocity 40 km/h towards an observer and emits a sound of frequency 2000 Hz. If the velocity of sound is 1220 km/h, then the apparent frequency heard by the observer is 2068 Hz.
Hint:
Apparent frequency heard by the observer.
Data:
v = 1220 km/h (or) 339 ms-1
vS = 40 km/h (or) 11.1 ms-1
n = 2000 Hz
n' = `("v"/("v"-"v"_s))` n
= `(339/(339-11.1))` x 2000
= 1.03385 x 2000
= n' = 2068 Hz.
APPEARS IN
संबंधित प्रश्न
Select the correct alternative :
The speed of sound in water is
During a thunderstorm, the sound of a thunder is heard after the lightning is seen. Why?
What is the time-period of a tuning fork whose frequency is 200 Hz?
A cricket ball is seen to hit the bat first and the sound of hitting is heard a little later. Why?
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?
Sunil is standing between two walls. The wall closest to him is at a distance of 660 m. If he shouts, he hears the first echo after 4 s and another after another 2 seconds.
- What is the velocity of sound in air?
- What is the distance between the two walls?
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?
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)
The thunder of cloud is heard 9.8 seconds later than the flash of lightning. If the speed of sound in air is 330 ms–1, what will be the height of the cloud?
On which factors does the speed of sound in the gaseous medium depend?
