# Hydrostatic Pressure

## Pascal's Principle

Pressure and force in fluids; hydraulic lifts and equivalence of work on either side of lift.

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• Watch {}video clip from Lecture 27 (0:00 - 7:32)

## Hydrostatic Pressure

Definition; incompressible fluids and dP/dy=-ρg. Pressure in paint cans filled with air and water.

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• Watch {}video clip from Lecture 27 (7:32 - 16:14)

## Pressure Dependence on Height

Using dP/dy=-ρ pressure from liquid weight and proportionality to height, density; atmospheric pressure.

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• Watch {}video clip from Lecture 27 (16:14 - 23:53)

## Barometers

Measuring pressure using Pascal's principle; mercury and water barometers.

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## Overpressure and Submarines

Cornelius von Drebbel's 5-m submarine; overpressure; compression of evacuated can.

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• Watch {}video clip from Lecture 27 (30:33 - 35:39)

## Manometers and Snorkeling

Explanation of manometers; setup for being able to breathe underwater through snorkel tube.

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• Watch {}video clip from Lecture 27 (35:39 - 41:41)

## Snorkeling and Drinking from Straws

Demonstration of maximum snorkeling depth; drinking from a 5-meter straw.

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• Watch {}video clip from Lecture 27 (41:41 - 49:34)

## Archimedes' Principle

Pascal's law defined; Archimedes' principle defined (Fb = ρ*g*V); mass density and pressure defined; equation for pressure as a function of depth derived.

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4-part problem; weight before and after rock is lowered into a beaker of water and density of rock; weight after pinning sphere to bottom.

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## Properties of Fluids

Forces involved in air pressure and buoyancy.

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## Oscillating Rod in Water

Calculating period of oscillation for vertical rod in water given displacement and pressure.

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