Fluid Mechanics and Properties

A comprehensive set of flashcards covering fluid mechanics principles, properties, and related calculations.

Why are gases easier to compress than liquids and solids?

Gases have more space between their molecules, allowing them to be compressed more easily.

How do gases differ from liquids?

Gases maintain neither size nor shape, while liquids maintain size but not shape.

What is the relationship between pressure and the sharpness of a knife?

Greater pressure is exerted with sharper knives due to their smaller area.

Why does a dull hypodermic needle hurt more than a sharp one?

A dull needle has a larger area, leading to less pressure and more pain upon insertion.

How is the outward force of an air tank balanced?

The outward force is balanced by the internal pressure against the walls of the tank.

In the context of melting ice, which ice chunk contributes more to water level rise?

The melting iceberg contributes more, as it displaces its weight when floating.

What is the volume of 1 troy ounce of pure gold?

The volume is approximately 24.57 cm³.

What is the volume in liters of 34.5 kg of mercury?

The volume is approximately 46.1 liters.

What pressure is exerted by a phonograph needle supporting 1.00g on a circle with a radius of 0.200mm?

The pressure is approximately 3183 N/m².

What does the SI unit of ρgh represent?

It equates to pressure, measured in N/m².

What extra force is exerted against the bottom of the jug if a cork is pounded with 120-N force?

The extra force exerted can be calculated using the difference in pressure due to the cork.

What is the average density of a log that floats with 20.0% of its length above water?

The average density is 0.8 g/cm³.

What fraction of a body with density 995 kg/m³ will be submerged in freshwater?

Approximately 0.995 (or 99.5%).

What are examples of incompressible and compressible substances?

Incompressible: water; Compressible: gases like air.

How does placing your thumb on a garden hose affect water distance?

It increases flow velocity when released, allowing water to squirt farther.

Why does fountain water broaden as it rises?

Due to reduction in pressure and increase in velocity, allowing the stream to expand.

What is the average flow rate of gasoline to an engine traveling at 100 km/h?

Approximately 100 cm³/s.

How long would it take to fill a swimming pool of 80,000 L at 60 L/min?

It would take approximately 1,333 minutes, or about 22.2 hours.

How long would it take to fill the pool using a river flowing at 5000 m³/s?

It would take a fraction of a second, practically instantaneous.

How do you verify that pressure has units of energy per unit volume?

Pressure is defined as force per area, and energy is force times distance, leading to units of J/m³.

What will the pressure reading of a pitot tube be at 700 km/h if it reads 15.0 mm Hg at 200 km/h?

It will be higher due to the relationship between pressure and speed.

What is Pascal's Principle?

When pressure is applied to a confined fluid, it is transmitted undiminished throughout the fluid.

What is the atmospheric pressure at sea level in Pa?

1.013 x 10^5 Pa.

What does Archimedes' Principle state?

The buoyant force on an object is equal to the weight of the fluid displaced by it.

What unit of fluid flow is represented by Q?

Flow rate, expressed in m³/s.

What happens to flow rate and velocity in a narrowed pipe?

As the area decreases, velocity increases while flow rate remains constant.

What is Bernoulli's Principle?

In a fluid flow, an increase in velocity leads to a decrease in pressure.

How is static and dynamic pressure different according to Bernoulli's principles?

Static pressure increases with depth while dynamic pressure considers fluid velocity.

What is the relationship between flow rate, area, and fluid velocity?

Q = Av, where Q is flow rate, A is cross-sectional area, and v is fluid velocity.