7.2 Pressure in liquids [Mastery check]

Diagram shows the design of a dam. Why does the thickness of the dam increase with its depth?

• The design of this structure is stronger.

• Water pressure increases with depth.

• The cost of construction is lower.

• Water pressure acts uniformly in all directions.

A submarine has a surface area of 300 m².

The density of sea water is 1050 kg m^–3.

At what depth under the sea, will the additional pressure on the submarine be 5 × 10⁵ Pa?

[Take g = 10 N kg^–1]

• 47.6 m

• 67.6 m

• 87.6 m

• 57.6 m

A coin sinks to a depth of 5 m in a liquid of density 800 kg m^–3. At what depth, in a different liquid of density 600 kg m^–3, will the coin be subjected to the same pressure?

• 6.67 m

• 8.67 m

• 9.67 m

• 5.67 m

The figure shows a pond with two fish P and Q.

What is the correct relation of the water pressures on fish P and fish Q?

• Water pressure on fish Q > Water pressure on fish P.

• Water pressure on fish Q < Water pressure on fish P.

• Water pressure on fish Q = Water pressure on fish P.

The pressure of water exerted on the fishes is P_X, P_Y and P_Z respectively.
Which comparison is correct about the pressure exerted on the fishes?

• P_Z > P_Y > P_X 
• P_Z = P_X < P_Y
• P_Z = P_X > P_Y
• P_Z < P_X < P_Y

In the image which hole will allow the water to travel furthest?

• A

• B

• C

Which of the following does not affect the pressure beneath the surface of a liquid?

• Strength of the gravitational field

• Area of the liquid surface

• Density of the liquid

• Depth of the liquid

The diagrams show, to the same scale, the vertical sections of a set of circular vessels, each containing the same depth of water.

• The water exerts the same pressure on the base of each vessel.

• The water exerts the greatest pressure on the base of vessel S.

• The water exerts the greatest pressure on the base of vessel P.

• The water exerts the same force on the base of each vessel.

The pressure exerted by a liquid

• increases with depth.

• decreases with depth.

• is constant

• first increases and then decreases.

A diver is at 100 m depth in a sea. If density of the sea water is 1025 kg m^-3 , calculate the water pressure acting on the diver? [g = 9.8 N/kg]

• 1004.5 kPa

• 1000.0 kPa

• 1025.0 kPa

• 1020.0 kPa