Advertisements
Advertisements
Question
A man is standing between two vertical walls 680 m apart. He claps his hands and hears two distinct echoes after 0.9 seconds and 1.1 seconds respectively. What is the speed of sound in the air?
Advertisements
Solution
Given data is
d = 680 m
t1 = 0.9 s
t2 = 1.1 s
v = ?
Velocity = `"Distance travelled by sound"/"Time taken"`
V= `(2"d")/t`
d1 = `("vt"_1)/2` & d2 = `("vt"_2)/2`
d = `"v"/2` (t1 + t2)
V = `(2"d")/(("t"_1 + "t"_2))`
= `(2xx680)/((0.9 + 1.1))`
= `(2xx680)/2`
V= 680 ms-1
APPEARS IN
RELATED QUESTIONS
An echo returned in 3 s. What is the distance of the reflecting surface from the source, given that the speed of sound is 342 m s−1?
A man is standing at a distance of 12 m from a cliff. Will he be able to hear a clear echo of his sound? Give a reason for your answer.
Fill in the blank with suitable word :
An echo is simply a ................... sound.
Why do we hear more clearly in a room with curtains than in a room without curtains ?
The speed of sound in water is 1500 metres per second. How far away from an under-sea rock should a deep sea diver be so that he can hear his own echo ?
What is meant by 'reflection of sound' ? What type of surfaces are the best for reflecting sound ?
State the laws of reflection of sound.
What is an echo ? How is echo formed ?
When sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound remain the same. Do you hear an echo sound on a hotter day? Justify your answer.
______ is an image obtained by the use of reflected ultrasonic waves.
