Question

What
is the approximate change in density
of waterin a lake at a
depth of 4oom
below the surface ? The density of water
at the rinface
1050 kg/m2 and Bulk
modules of water is 3x109N/m2;
(A) 4kg/m3
(B) 2kg/m3
(c) 6kg/m3
6
es
3
Ekg/m3​

Answer 1

Answer:

Solution

At a depth x m below the surface the pressure P=ρgx

Bulk strain

=

B

P

=

B

ρgx

⇒

V

ΔV

=

B

ρgx

⇒ΔV=

B

ρgxV

Density at x m below the surface ρ

′

=

v

′

ρV

(v

′

=v−Δv)

⇒

ρ

˙

′

=

V−

β

ρgxV

βV

⇒s

′

=

Bρgx

ρB

⇒ρ

′

=

2×10

9

−1030×9.8×400

1030×2×10

9

⇒ρ

′

= 1032 kg/m

3

Δρ=1032−1030=2 kg/m

3

Ans: B