Sound signal of frequency 40 kHz is sent vertically into sea water. The signal gets reflected from the ocean bed and returns to the surface 0.60 s after it was emitted. The speed of sound in sea water is `1500 ms^(-1)`. What is the depth of the sea and wavelength of this signal in water.

Options

A. 450 m, 3.75 cm
B. 9000m, 3.75 cm
C. 4500 m, 5 cm
D. 9000 m, 5 cm.

Answer

A

Explanation

Let depth of the sea bed is d. The total distance travelled by the signal is 2d. Now applying the equation.
`2d=vt`
`implies 2d=(1500) (0.60)`
`implies d=450 m`
Again using the equation
`v=n lambda`
`implies lambda =v/n`
`=(1500 ms^(-1))/(40 xx 10^(3) s^(-1))=3.75 cm`