The speed of sound in air is 344 m/s. In order to hear distinct echoes in air, the distance of the obstacle from the source of sound should be:
The speed of sound in air is 344 m/s. In order to hear distinct echoes in air, the distance of the obstacle from the source of sound should be:
The correct option is A at least 17.2 m
Taking the speed of sound in air to be 344 m/s and the minimum time gap between direct sound and reflected sound to be 0.1 seconds.
the distance travelled by sound in 0.1 s = 344 × 0.1 = 34.4 m.
Since the reflected sound wave travelled twice the distance between obstacle and source, the distance between the source and obstacle = 17.2 m.
17.2 m is the distance at which an obstacle must be placed so that the time difference between the direct sound and the echo is 0.1s.
As we know an echo can be distinguished if the time difference is at least 0.1 seconds. So, the minimum distance an obstacle can be placed so as to hear a distinct echo is 17.2 m.
In order to hear distinct echoes in the air, the distance of the obstacle from the source of sound should be at least 17.2 m
at least 17.2 m
Taking the speed of sound in air to be 344 m/s and the minimum time gap between direct sound and reflected sound to be 0.1 seconds.
the distance travelled by sound in 0.1 s = 344 × 0.1 = 34.4 m.
Since the reflected sound wave travelled twice the distance between obstacle and source, the distance between the source and obstacle = 17.2 m.
17.2 m is the distance at which an obstacle must be placed so that the time difference between the direct sound and the echo is 0.1s.
As we know an echo can be distinguished if the time difference is at least 0.1 seconds. So, the minimum distance an obstacle can be placed so as to hear a distinct echo is 17.2 m.
In order to hear distinct echoes in the air, the distance of the obstacle from the source of sound should be at least 17.2 m
