Question

The splash is heard after 4.22 sec after the stone is dropped into a well depth of 78.4 m. The velocity of sound is

Answer 1

Hi ...dear..
here is your answer!!!..

..........
let stone take time Tto reach down ...
now we know that...
S =ut+ 1/2 gt²....
here u = 0 .as stone is dropped freely....
g. should be taken as standard which is 9.8m/s²....
.
s=height......
putting these values.....
-78.4=0*t-1/2(g)t*t.........
.we get
t=4
Now the time taken by sound i
s=4.22-4
=0.22s

speed of sound is = 78.4/0.22=356.36....m/s..
hope this helps you!!!
Regards Brainly Star Community
#shubhendu

Answer 2

Answer:

356.36 m/s

Explanation:

Hi dear,

Here is your answer....

Let stone take time to reach down = t

(.:Now we know that)

S =ut+ 1/2 gt² (here, u = 0, as stone is dropped freely....,

                                 g = 9.8m/s²,as it should br taken as standard, i.e., 9.8m/s²

                                 S= -78.4m, given

                                 T = take time to reach down)

putting these values:-

-78.4m = 0 × t - $\frac{1}{2}$ (g) t²

We get

t = 4

Now the time taken by sound is

  = 4.22-4

  = 0.22s

speed of sound is

  = 78.4/0.22

  = 356.36 m/s