Question

An ultra sound equipment installed at a height of 80 m/s above sea water surface sends out ultrasound that returns from the sea water is 1500m/s and that through air is 320m/s then the depth of sea at that place is?

Answer 1

We know

That 2d=v*t

So after calculation answer will be 4900 m

Answer 2

Question should be corrected as below:

An ultrasound equipment installed at a height of 80 m above sea water surface sends out ultrasound that returns from the sea bed and is detected after 5.4 s.if the speed of ultrasound through sea water is 1500 m/s and that through air is 320 m/s then find the depth of sea at that place is?

Answer:

Time taken from transmission to reception = 5.4 seconds

time to travel in air + time to travel in water = 5.4 s------ (1)

But we know that, time = distance/ velocity

Then we can modify equation (1) as below,

$2* (80/320) + 2*(d/1500) = 5.4$

          $(80/160) + (d/750) = 5.4$

                              $d/750 = 5.4 - 0.5$

                                     $d = 4.9 *750$

                                    $d = 3675 m$

Answer : Depth of the water = d = 3675 m