Question

how will you calculate the minimum distance of an echo

Answer 1

by taking speed of sound and time as 0.1 s
apply the formula 2d = vt
u can calculate minimum distance.
i think speed of sound is 340 m/s
so,
2d=340 x 1 /10
d = 34/ 2
d= 17 m

Answer 2

The minimum distance of an echo is 17.15 m

Explanation:

The distance traveled by sound to create an echo is two times the distance between the source and obstacle.

So, the distance traveled by sound is 2d.

We know that,

$\text { Distance }=\text {Velocity} \times \text{Time}$

Here,

$2 d=\text {Velocity} \times \text{Time}$

Let velocity is the speed of sound in air which is equal to 343 m/s and time is 0.1 s as this the time required by human to hear two sounds clearly.

To find the minimum distance d,

$d=\frac{V e l o c i t y \ \times \ T i m e}{2}$

So,

$d=\frac{343 \times 0.1}{2}$

Therefore, the minimum distance is 17.15 m