Fluid Mechanics and Atmospheric Pressure

These flashcards cover key concepts and definitions related to fluid mechanics and atmospheric pressure.

At what angle do the forces due to pressure act on a given surface in a fluid?

At right angles (normal to) the surface.

What is the equation used to calculate pressure?

Pressure = Force/Area.

What is the unit of pressure?

Pascals (Pa).

How does the density of the atmosphere change with increasing altitude?

The atmosphere becomes less dense as altitude increases.

Why does atmospheric pressure decrease with an increase in height?

Because the quantity of air molecules decreases, resulting in lower weight and pressure.

What defines the Earth's atmosphere?

A thin layer of gas surrounding the Earth.

How does pressure in fluids change with increasing depth?

Pressure increases due to the increasing mass of liquid above that depth.

What happens to pressure in fluids as density increases?

Pressure increases as the number of particles and fluid weight increases.

What equation represents the magnitude of pressure in liquids at different depths?

P = hρg (Pressure = Column height x density x gravitational field strength).

What causes upthrust on objects submerged in a fluid?

Higher pressure below the object than above it results in an upwards force called upthrust.

What determines whether an object will sink or float?

Upthrust, weight, and density of the fluid.

Can an object with a density greater than that of water float? Why or why not?

No, it cannot float because it won't displace enough water to generate sufficient upthrust.

What is the relationship between pressure and area in fluids?

If the area remains constant while the force increases, pressure will increase.

Why is pressure greater at greater depths in a fluid?

Greater depth leads to more weight of the liquid above, increasing pressure.

How is atmospheric pressure created?

By collisions of air molecules in the atmosphere.

Is the pressure at the surface of a fluid higher than at a submerged depth?

No, pressure is higher at submerged depths due to the weight of the fluid above.

What affects the amount of upthrust an object experiences in a fluid?

The density of the fluid and the volume of fluid displaced.

What happens to the weight of air as altitude increases?

The weight of air decreases as altitude increases.

What principle explains why a ship floats?

The principle of upthrust, where the weight of the fluid displaced equals the weight of the ship.

What will happen if an object's weight is greater than the upthrust it experiences?

The object will sink.