Q.(a) The pressure at depth below the surface of a liquid open to the atmosphere is greater than atmospheric pressure. Excess pressure at depth is called ______ .

The SI unit of pressure is the pascal (Pa) = 1 N/m².

Pressure P is defined as the force F acting normally (perpendicularly) per unit area A: P = F/A. Since force is measured in newtons and area in square metres, pressure has SI unit N/m², which is given the spe …

Blood pressure is greater at the feet because of the greater height of blood column above them, exactly as predicted by the hydrostatic pressure formula P = hρg — so R correctly explains A.

Checking Assertion (A): In a standing human, blood pressure measured at the feet is indeed greater than that measured near the brain/head. This is TRUE.

Checking Reason (R): The pressure at a depth h inside a liquid column of density ρ is given by:

P = P0 + hρg

where P0 is the pressure at the top of the column. This shows pressure increases with the height (depth) of the liquid column above the point of measurement. This statement is TRUE.

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Total pressure = 1 atm (air) + rho g h (about 1 atm) = 2 atm. Answer (B).

Absolute pressure at depth h: P = P_atm + rho g h.

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Hydrostatic pressure is given by P = h * rho * g, which depends only on the depth (height of liquid column) and the liquid's density -- famously independent of the container's shape or cross-sectional area (this is the basis of the hydrostatic paradox).

The pressure at a depth h inside a static liquid of density rho is:

P = h * rho * g

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Liquid stands at the same level in differently shaped connected vessels because static pressure depends only on depth, not on shape or volume - this is the hydrostatic paradox.

For a liquid at rest, the pressure at a depth h below the free surface is P = P0 + rho g h, where P0 is the atmospheric pressure. This shows the pressure depends only on the depth h, the density rho and g - and not on the cross-sectional shape of the container or how much liquid it holds.

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Pressure inside a liquid at depth h is given by P = hρg — it depends only on the depth (height of liquid column) and the liquid's density, never on the shape or cross-sectional area of the container.

The formula for pressure at a point inside a liquid at rest, at depth h below the free surface, is:

P = h ρ g (+ atmospheric pressure, if considering absolute pressure)

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Pressure head is pressure expressed as an equivalent height of a fluid column: h = P/(rho g).

In Bernoulli's equation, pressure (P), kinetic energy per unit volume ((1/2) rho v^2), and gravitational potential energy per unit volume (rho g h) are all expressed as energy per unit volume and can each be converted into an equivalent "head" (a height):

Pressure head h = P / (rho g)

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