Two children are at opposite ends of an aluminium rod. One strikes the end of rod with a stone. Find the ratio of times taken by sound wave in air and in aluminium to reach the second child (Given: Speed of sound in air = 346 m/s; Speed of sound in aluminium = 6240 m/s)

Question

Philoid · Accepted Answer

Let, the length of aluminium rod is l.

Now, firstly we calculate the speed of sound in air.

We know that,

Speed of sound (in air) =

346 =

Time taken in air = (i)

Now, speed of sound in aluminium.

We know that,

Speed of sound (in aluminium) =

6420 =

Time taken in aluminium = (ii)

Now by dividing (i) and (ii), we get:

_{= 6420/346}

=

Therefore, the ratio is 18.55:1