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Weight (object)
{{short description, none A weight (also known as a mass) is an object, normally with high density, whose chief task is to have mass and exert weight (through gravity). It is used for different purposes, such as in: *Anchor * Balance weight * Ballast * Bob *Counterweight A counterweight is a weight (object), weight that, by applying an opposite force, provides balance and stability of a machine, mechanical system. The purpose of a counterweight is to make lifting the load faster and more efficient, which saves e ... * Fishing sinker * Paperweight * Plumb bob * Tuned mass damper * Weight training equipment * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be used: \rho = \frac, where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate this quantity is more specifically called specific weight. For a pure substance, the density is equal to its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium is the densest known element at standard conditions for temperature and pressure. To simplify comparisons of density across different systems of units, it is sometimes replaced by the dimensionless quantity "relative den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass
Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physics. It was found that different atoms and different elementary particle, elementary particles, theoretically with the same amount of matter, have nonetheless different masses. Mass in modern physics has multiple Mass in special relativity, definitions which are conceptually distinct, but physically equivalent. Mass can be experimentally defined as a measure (mathematics), measure of the body's inertia, meaning the resistance to acceleration (change of velocity) when a net force is applied. The object's mass also determines the Force, strength of its gravitational attraction to other bodies. The SI base unit of mass is the kilogram (kg). In physics, mass is Mass versus weight, not the same as weight, even though mass is often determined by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weight
In science and engineering, the weight of an object is a quantity associated with the gravitational force exerted on the object by other objects in its environment, although there is some variation and debate as to the exact definition. Some standard textbooks define weight as a Euclidean vector, vector quantity, the gravitational force acting on the object. Others define weight as a scalar quantity, the magnitude of the gravitational force. Yet others define it as the magnitude of the reaction (physics), reaction force exerted on a body by mechanisms that counteract the effects of gravity: the weight is the quantity that is measured by, for example, a spring scale. Thus, in a state of free fall, the weight would be zero. In this sense of weight, terrestrial objects can be weightless: so if one ignores Drag (physics), air resistance, one could say the legendary apple falling from the tree, on its way to meet the ground near Isaac Newton, was weightless. The unit of measurement fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity
In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force between objects and the Earth. This force is dominated by the combined gravitational interactions of particles but also includes effect of the Earth's rotation. Gravity gives weight to physical objects and is essential to understanding the mechanisms responsible for surface water waves and lunar tides. Gravity also has many important biological functions, helping to guide the growth of plants through the process of gravitropism and influencing the circulation of fluids in multicellular organisms. The gravitational attraction between primordial hydrogen and clumps of dark matter in the early universe caused the hydrogen gas to coalesce, eventually condensing and fusing to form stars. At larger scales this results in galaxies and clust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchor
An anchor is a device, normally made of metal, used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ', which itself comes from the Greek (). Anchors can either be temporary or permanent. Permanent anchors are used in the creation of a mooring, and are rarely moved; a specialist service is normally needed to move or maintain them. Vessels carry one or more temporary anchors, which may be of different designs and weights. A sea anchor is a drag device, not in contact with the seabed, used to minimize drift of a vessel relative to the water. A drogue is a drag device used to slow or help steer a vessel running before a storm in a following or overtaking sea, or when crossing a bar in a breaking sea. Anchoring Anchors achieve holding power either by "hooking" into the seabed, or weight, or a combination of the two. The weight of the anchor chain can be more than that of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weighing Scale
A scale or balance is a device used to measure weight or mass. These are also known as mass scales, weight scales, mass balances, massometers, and weight balances. The traditional scale consists of two plates or bowls suspended at equal distances from a fulcrum. One plate holds an object of unknown mass (or weight), while objects of known mass or weight, called '' weights'', are added to the other plate until mechanical equilibrium is achieved and the plates level off, which happens when the masses on the two plates are equal. The perfect scale rests at neutral. A spring scale will make use of a spring of known stiffness to determine mass (or weight). Suspending a certain mass will extend the spring by a certain amount depending on the spring's stiffness (or spring constant). The heavier the object, the more the spring stretches, as described in Hooke's law. Other types of scales making use of different physical principles also exist. Some scales can be calibrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballast
Ballast is dense material used as a weight to provide stability to a vehicle or structure. Ballast, other than cargo, may be placed in a vehicle, often a ship or the gondola of a balloon or airship, to provide stability. A compartment within a boat, ship, submarine, or other floating structure that holds water is called a ballast tank. Water should be moved in and out from the ballast tank to balance the ship. In a vessel that travels on the water, the ballast will be kept below the water level, to counteract the effects of weight above the water level. The ballast may be redistributed in the vessel or disposed of altogether to change its effects on the movement of the vessel. History The basic concept behind the ballast tank can be seen in many forms of aquatic life, such as the blowfish or members of the argonaut group of octopus. The concept has been invented and reinvented many times by humans to serve a variety of purposes. In the fifteenth and sixteenth century, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bob (physics)
A bob is a heavy object (also called a "weight" or "mass") on the end of a pendulum found most commonly, but not exclusively, in pendulum clocks. Reason for use Although a pendulum can theoretically be any shape, any rigid object swinging on a pivot, clock pendulums are usually made of a weight or ''bob'' attached to the bottom end of a rod, with the top attached to a pivot so it can swing. The advantage of this construction is that it positions the centre of mass close to the physical end of the pendulum, farthest from the pivot. This maximizes the moment of inertia, and minimises the length of pendulum required for a given period. Shorter pendulums allow the clock case to be made smaller, and also minimize the pendulum's air resistance. Since most of the energy loss in clocks is due to air friction of the pendulum, this allows clocks to run longer on a given power source. Use in clocks Traditionally, a clock pendulum bob is a round flat disk, lens-shaped in sect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counterweight
A counterweight is a weight (object), weight that, by applying an opposite force, provides balance and stability of a machine, mechanical system. The purpose of a counterweight is to make lifting the load faster and more efficient, which saves energy and causes less wear and tear on the lifting machine. Counterweights are often used in traction force, traction elevator, lifts (elevators), Crane (machine), cranes and fair, funfair rides. In these applications, the expected load multiplied by the distance that load will be spaced from the central support (called the "tipping point") must be equal to the counterweight's mass times its distance from the tipping point in order to prevent over-balancing either side. This distance times mass is called the Moment (physics), load moment. By extension, a counterbalance force balances or offsets another force, as when two objects of equal weight, power, or influence are acting in opposition to each other. Examples ;Trebuchet: There are fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishing Sinker
A fishing sinker, plummet, or knoch is a weight used in conjunction with a fishing lure or hook to increase its rate of sink, anchoring ability, and/or casting distance. Fishing sinkers may be as small as for applications in shallow water, and even smaller for fly fishing applications, or as large as several pounds (>1 kg) or considerably more for deep sea fishing. They are formed into many different shapes for diverse fishing applications. Environmental concerns surround the usage of lead and other materials in fishing sinkers. Types A large variety of sinkers exist, whose specific use depends on the fish pursued, the environment, the current, and personal preference. Pyramid sinkers Pyramid sinkers are shaped like a pyramid and are used when it is desirable to anchor on the bottom of water bodies. They are attached to the terminal end of fishing line by loops of bra. Barrel or egg sinkers Barrel or egg sinkers are rounded and often bead-like with a narrow hole through wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paperweight
A paperweight is a small solid object heavy enough, when placed on top of papers, to keep them from blowing away in a breeze or from moving under the strokes of a painting brush (as with Chinese calligraphy). While any object, such as a stone, can serve as a paperweight, decorative paperweights of metal, glass, jade or other material are also produced, either by individual artisans or factories. In the West, the decorative paperweights are usually in limited editions, and are collected as works of fine glass art, some of which are also exhibited in museums. First produced in about 1845, particularly in France, such decorative paperweights declined in popularity before undergoing a revival in the mid-twentieth century. Basic features Decorative glass paperweights have a flat or slightly concave base, usually polished but sometimes frosted, cut in one of several variations (e.g. star-cut bases have a multi-pointed star, while a diamond cut base has grooves cut in a criss-cros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
