Quicksand is loose, water-logged soil that yields easily to weight or pressure. It can be formed when sand, silt, clay, or other grainy soil is saturated or supersaturated by water flowing from below ground (such as from an underground spring) with enough pressure to separate and suspend the grains. The undisturbed sand often is or appears solid until some shock or sudden increase in pressure, such as a person stepping on ...

Read more here: » Quicksand: Encyclopedia - Quicksand

See also:

Quicksand band, Quicksand band - History, Quicksand band - Post-Quicksand, Quicksand band - Discography, Quicksand band - Albums, Quicksand band - EPs / Singles

Read more here: » Quicksand band: Encyclopedia II - Quicksand band - History

Sand is an example of a class of materials called granular matter. Sand is a naturally occurring, finely divided rock, comprising particles or granules ranging in size from 1⁄16 to 2 millimeters. An individual particle in this range size is termed a sand grain. The next smaller size class in geology is silt: particles below 1⁄16 mm down to 1⁄256 mm (0.004 mm) in size. The next larger size class above sand is gravel, with particles ranging up to 6 ...

Including:

• Sand - Uses of sand
• Sand - Hazards of sand

Read more here: » Sand: Encyclopedia - Sand

In physics, buoyancy is an upward force on an object immersed in a fluid (i.e. a liquid or a gas), enabling it to float or at least to appear lighter. Buoyancy is important for many vehicles such as boats, ships, balloons, and airships. Buoyancy - Forces and equilibrium. The buoyancy provides an upward force on the object. According to Newton's first law of motion, if the upward forces (including the buoyancy) balance the downward forces (including the weight) the object will remain at rest. Otherwise, it w ...

Including:

• Buoyancy - Forces and equilibrium
• Buoyancy - Archimedes' Principle
• Buoyancy - Density
• Buoyancy - Acceleration
• Buoyancy - Links

Read more here: » Buoyancy: Encyclopedia - Buoyancy

Writing in Nature, rheologist Detlef Lohse and coworkers of University of Twente in Enschede, Netherlands allowed air to flow through very fine sand (typical grain diameter was about 40 micrometers) in a container with a perforated base. They then turned the air stream off before the start of the experiment and allowed the sand to settle: the packing fraction of this sand was only 41% (compared 55–60% for untreated sand). Lohse found that a weighted ping pong ball (radius 2 cm, mass 133 g), when released from just above the s ...

See also:

Dry quicksand, Dry quicksand - Scientific research, Dry quicksand - Occurrences in literature and otherwise

Read more here: » Dry quicksand: Encyclopedia II - Dry quicksand - Scientific research

Nella Larsen's first novel tells the story of Helga Crane, a fictional character clearly based on Larsen herself. Crane is the daughter of a Danish mother and a black father, who goes to various places and communities in search of somewhere she feels her home. Her travels bring her in contact with many of the communities Larsen herself knew: "Naxos", a Southern Negro school based on Tuskegee; Chicago, where her white relatives shun her; Harlem, where she finds a refined but often hypocritical black middle class obsessed with the "race proble ...

See also:

Nella Larsen, Nella Larsen - Biography, Nella Larsen - Quicksand, Nella Larsen - Passing, Nella Larsen - Read on

Read more here: » Nella Larsen: Encyclopedia II - Nella Larsen - Quicksand

Nella Larsen went by various names throughout her life, including Nellie Walker, Nellye Larson, Nellie Larsen and, finally, Nella Larsen as well as by her married name Nella Larsen Imes. She was born in Chicago on April 13, 1891 as Nellie Walker, the daughter of the Danish Marie Hanson and Peter Walker, a West Indian man of color from Saint Croix. Her mother later married a white man. As a result, she grew up as the black child of a lower-middle class white household. Her family, perhaps ashamed of her race ...

See also:

Nella Larsen, Nella Larsen - Biography, Nella Larsen - Quicksand, Nella Larsen - Passing, Nella Larsen - Read on

Read more here: » Nella Larsen: Encyclopedia II - Nella Larsen - Biography

Sand is often a principal component of the aggregate used in the preparation of concrete. Sand manufactured at rock crusher plants for use as an aggregate is called mansand. Graded sand is used as an abrasive in sandblasting and is also used in media filters for filtering water. Brick manufacturing plants use Sand as an additive with a mixture of clay and other materials for manufacturing bricks. Sandy soils are ideal for certain crops such as watermelons, peaches, and peanuts and are often preferred for intensive dairy farming because of thei ...

See also:

Sand, Sand - Uses of sand, Sand - Hazards of sand

Read more here: » Sand: Encyclopedia II - Sand - Uses of sand

Although Archimedes' principle gives the force on a buoyant object, this does not allow the direct determination of the acceleration of the object in the usual way using Newton's second law. This is because as well as accelerating the object the fluid also has to be dynamically displaced, resulting in drag. While Archimedes' principle is hydrostatic force, it must be taken into account, even in hydrodynamical situations. A simple case would be that of a submerged, sphere that is twice as dense as water starting at rest and as it first ...

See also:

Buoyancy, Buoyancy - Forces and equilibrium, Buoyancy - Archimedes' Principle, Buoyancy - Density, Buoyancy - Acceleration, Buoyancy - Links

Read more here: » Buoyancy: Encyclopedia II - Buoyancy - Acceleration

Although Archimedes' principle gives the force on a buoyant object, this does not allow the direct determination of the acceleration of the object in the usual way using Newton's second law. This is because as well as accelerating the object, the fluid also has to be dynamically displaced- resulting in drag. While Archimedes' principle is hydrostatic force, it must be taken into account, even in hydrodynamical situations. A simple case would be that of a submerged sphere that is twice as dense as water starting at rest and as it first ...

See also:

Buoyancy, Buoyancy - Forces and equilibrium, Buoyancy - Archimedes' principle, Buoyancy - Density, Buoyancy - Acceleration

Read more here: » Buoyancy: Encyclopedia II - Buoyancy - Acceleration

Bags of sand now typically carry labels warning the user to wear respiratory protection and avoid breathing the fine silica dust. There have been a number of lawsuits in recent years where workers have sought damages after they developed silicosis, a lung disease caused by inhalation of fine silica particles. People have been severely injured and even killed after digging sand "caves" in large dunes, sandhills, or even on beaches when ...

See also:

Sand, Sand - Uses of sand, Sand - Hazards of sand

Read more here: » Sand: Encyclopedia II - Sand - Hazards of sand

The buoyancy provides an upward force on the object. According to Newton's first law of motion, if the upward forces (including the buoyancy) balance the downward forces (including the weight) the object will remain at rest. Otherwise, it will accelerate upwards or downwards. If such an object's compressibility is less than that of the surrounding fluid, it is in stable equilibrium and will, indeed, remain at rest, but if its compressibility is greater, its equilibrium is unstable, and it will rise and expand on the slightest upward perturbation, or fall a ...

See also:

Buoyancy, Buoyancy - Forces and equilibrium, Buoyancy - Archimedes' Principle, Buoyancy - Density, Buoyancy - Acceleration, Buoyancy - Links

Read more here: » Buoyancy: Encyclopedia II - Buoyancy - Forces and equilibrium

It was the ancient Greek, Archimedes of Syracuse, who first discovered the law of buoyancy, sometimes called Archimedes' principle: The buoyant force is equal to the weight of the displaced fluid. The story of Archimedes discovering buoyancy, while sitting in his bathtub, is described in Book 9 of De architectura by Vitruvius. Typically, the weight of the displaced fluid is directly proportional to the volume of their displaced fluid (specifically if the surrounding fluid is of uniform density.) Thus, among objects with equal masses, ...

See also:

Buoyancy, Buoyancy - Forces and equilibrium, Buoyancy - Archimedes' Principle, Buoyancy - Density, Buoyancy - Acceleration, Buoyancy - Links

Read more here: » Buoyancy: Encyclopedia II - Buoyancy - Archimedes' Principle

If the weight of an object is less than the weight of the fluid that the object would displace if it was fully submerged, then the object is less dense than the fluid and it floats at a level so it displaces the same weight of fluid as the weight of the object. An object made of a material of higher density than the fluid, for example a metal object in water, can still float if it has a suitable shape (e.g. a hollow which is open upwards or downwards) that keeps a large enough volume of air below the surface level of the fluid. In that case, for the average density mentioned above, the air is included also, which may reduce this den ...

See also:

Buoyancy, Buoyancy - Forces and equilibrium, Buoyancy - Archimedes' Principle, Buoyancy - Density, Buoyancy - Acceleration, Buoyancy - Links

Read more here: » Buoyancy: Encyclopedia II - Buoyancy - Density

The buoyancy provides an upward force on the object. According to Newton's first law of motion, if the upward forces (including the buoyancy) balance the downward forces (including the weight) the object will remain at rest. Otherwise, it will accelerate upwards or downwards. If such an object's compressibility is less than that of the surrounding fluid, it is in stable equilibrium and will, indeed, remain at rest, but if its compressibility is greater, its equilibrium is unstable, and it will rise and expand on the slightest upward perturbation, or fall a ...

See also:

Buoyancy, Buoyancy - Forces and equilibrium, Buoyancy - Archimedes' principle, Buoyancy - Density, Buoyancy - Acceleration

Read more here: » Buoyancy: Encyclopedia II - Buoyancy - Forces and equilibrium

It was the ancient Greek, Archimedes of Syracuse, who first discovered the law of buoyancy, sometimes called Archimedes' principle: The buoyant force is equal to the weight of the displaced fluid. The story of Archimedes discovering buoyancy, while sitting in his bathtub, is described in Book 9 of De architectura by Vitruvius. Typically, the weight of the displaced fluid is directly proportional to the volume of their displaced fluid (specifically if the surrounding fluid is of uniform density.) Thus, among objects with equal masses, ...

See also:

Buoyancy, Buoyancy - Forces and equilibrium, Buoyancy - Archimedes' principle, Buoyancy - Density, Buoyancy - Acceleration

Read more here: » Buoyancy: Encyclopedia II - Buoyancy - Archimedes' principle

If the weight of an object is less than the weight of the fluid that the object would displace if it was fully submerged, then the object is less dense than the fluid and it floats at a level so it displaces the same weight of fluid as the weight of the object. An object made of a material of higher density than the fluid, for example a metal object in water, can still float if it has a suitable shape (e.g. a hollow which is open upwards or downwards) that keeps a large enough volume of air below the surface level of the fluid. In that case, for the average density mentioned above, the air is included also, which may reduce this den ...

See also:

Buoyancy, Buoyancy - Forces and equilibrium, Buoyancy - Archimedes' principle, Buoyancy - Density, Buoyancy - Acceleration

Read more here: » Buoyancy: Encyclopedia II - Buoyancy - Density

Larsen's second novel tells the story of two light skinned women: Irene Redfield and Clare Kendry. Clare Kendry is of mixed heritage, while Irene Redfield is fully African American but both are light enough to pass. Clare fully commits herself to passing and marries John Bellew, a white man who knows nothing of her heritage and calls her "Nig." Irene lives in Harlem, commits herself to racial uplift, and marries a Black doctor. The novel centers around the meeting of the two childhood friends later in life, and the unfolding of events as eac ...

See also:

Nella Larsen, Nella Larsen - Biography, Nella Larsen - Quicksand, Nella Larsen - Passing, Nella Larsen - Read on

Read more here: » Nella Larsen: Encyclopedia II - Nella Larsen - Passing

The player must maneuver a character known as Pitfall Harry through a maze-like jungle in an attempt to recover 32 treasures in a 20 minute period. Along the way, he must negotiate numerous hazards, including tar pits, quicksand, rolling logs, snakes, scorpions, walls, fire, and crocodiles. Harry may jump over or otherwise avoid these obstacles by timing his climbing and running, and in certain places ...

See also:

Pitfall!, Pitfall! - Gameplay, Pitfall! - History and development, Pitfall! - Sequels and licensing, Pitfall! - External link

Read more here: » Pitfall!: Encyclopedia II - Pitfall! - Gameplay

The area now known as Lincoln Park in Chicago was still primarily forest with stretches of grassland and occasional quicksand, and was virtually untouched by Europeans as late as the 1820s. In 1824 the United States Army built a small post near today's Clybourn and Armitage Avenues. Indian settlements existed along Green Bay Road, now called Clark Street (named after explorer George Rogers Clark), at the current inte ...

See also:

Lincoln Park Chicago, Lincoln Park Chicago - History, Lincoln Park Chicago - Neighborhood, Lincoln Park Chicago - Park

Read more here: » Lincoln Park Chicago: Encyclopedia II - Lincoln Park Chicago - History