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QJEEM19Phb3a6: JEE Main 2019 Physics - Class 11 JEEM19Phb3a6 Solution: A submarine experiences a pressure of 5.05 × 10 6 Pa at a depth …

A submarine experiences a pressure of 5.05 × 106 Pa at a depth of d1 in a sea. When it goes further to a depth of d2, it experiences a pressure of 8.08 × 106 Pa. Then d2 –d1 is approximately (density of water = 103 kg/m3 and acceleration due to gravity = 10 ms–2 ) :

Multiple Choice Options

  • A 600 m
  • B 400 m
  • C 300 m
  • D 500 m

Step-by-Step Verified Solution

The pressure experienced by a submarine at a certain depth in the sea is given by the formula:

P=ρghP = \rho g h

where:

  • PP is the pressure
  • ρ\rho is the density of the fluid (sea water in this case)
  • gg is the acceleration due to gravity
  • hh is the height (or depth in this case)

Given:

  • ρ=103 kg/m3\rho = 10^3 \, kg/m^3
  • g=10 m/s2g = 10 \, m/s^2

We are looking for the difference in depth, d2−d1d_2 - d_1 , which corresponds to the difference in pressure ΔP\Delta P :

ΔP=P2−P1=ρg(d2−d1)\Delta P = P_2 - P_1 = \rho g (d_2 - d_1)

Rearranging the above equation, we get:

d2−d1=ΔPρgd_2 - d_1 = \frac{\Delta P}{\rho g}

Given:

  • P2=8.08×106 PaP_2 = 8.08 \times 10^6 \, Pa
  • P1=5.05×106 PaP_1 = 5.05 \times 10^6 \, Pa

ΔP=P2−P1=8.08×106 Pa−5.05×106 Pa=3.03×106 Pa\Delta P = P_2 - P_1 = 8.08 \times 10^6 \, Pa - 5.05 \times 10^6 \, Pa = 3.03 \times 10^6 \, Pa

So,

d2−d1=3.03×106 Pa103 kg/m3×10 m/s2=303 md_2 - d_1 = \frac{3.03 \times 10^6 \, Pa}{10^3 \, kg/m^3 \times 10 \, m/s^2} = 303 \, m

The closest answer among the options provided is Option C, 300 m.

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