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Zorluk: OrtaSound Waves, Echoes, Pitch, Loudness, and Quality

A person standing at a stationary position between two tall parallel vertical walls fires a starter pistol. The person hears the first echo reflected from the nearer wall after 1.2 s1.2\text{ s} and the second echo from the farther wall after 1.8 s1.8\text{ s}. Given that the speed of sound in air is 340 m/s340\text{ m/s}, what is the total distance between the two walls in meters?

Cevap: 510 m

Cevap

The total distance between the two walls is 510 m510\text{ m}.
Because sound travels to each wall and reflects back to the observer, the distance to each wall is given by d=vt2d = \frac{v \cdot t}{2}. The distance to the nearer wall is d1=340×1.22=204 md_1 = \frac{340 \times 1.2}{2} = 204\text{ m}, and the distance to the farther wall is d2=340×1.82=306 md_2 = \frac{340 \times 1.8}{2} = 306\text{ m}. Since the observer is between the two walls, the total separation between the walls is 204 m+306 m=510 m204\text{ m} + 306\text{ m} = 510\text{ m}.

Adım Adım Çözüm

1
Calculate the distance from the observer to the nearer wall.
d1=204 md_1 = 204\text{ m}
The sound travels to the nearer wall and back in 1.2 s1.2\text{ s}, covering twice the distance to that wall.
2
Calculate the distance from the observer to the farther wall.
d2=306 md_2 = 306\text{ m}
The sound travels to the farther wall and back in 1.8 s1.8\text{ s}, covering twice the distance to that wall.
3
Add the two individual distances to find the total distance between the walls.
D=d1+d2=510 mD = d_1 + d_2 = 510\text{ m}
The observer is positioned between the two walls, so the separation distance is the sum of both distances.

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