## anonymous one year ago A sonar pulse is sent to the ocean bottom at 25°C, and it takes 1.20 s for the echo to come back. How deep is the bottom? 0.90 km , 0.92 km , 1.79 km, or 1.84 km ?

1. Michele_Laino

we have to know how much is the speed of sound inside a sea water

2. Michele_Laino

I found that value in my textbook: it is 1,460 m/sec

3. anonymous

oh oops sorry i am drawing the table now :P |dw:1433187822896:dw|

4. Michele_Laino

ok! ten we can pick 1,533 m/sec

5. anonymous

:)

6. Michele_Laino

so we can write: $\Large 1.2 = \frac{{2d}}{{1533}}$ where d is the requested deepness, there the factro 2, is to take account that we are dealing with the echo

7. Michele_Laino

factor*

8. anonymous

ok! and then we get this? 1839.6=2d d=919.8 ?

9. Michele_Laino

yes!

10. Michele_Laino

d=919.8 meters= 0.92 Km (approximated value)

11. anonymous

yay!! thank you!!:D

12. Michele_Laino

:)