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Impact (physics)
In mechanics, an impact is when two bodies collide. During this collision, both bodies decelerate. The deceleration causes a high force or shock, applied over a short time period. A high force, over a short duration, usually causes more damage to both bodies than a lower force applied over a proportionally longer duration. At normal speeds, during a perfectly inelastic collision, an object struck by a projectile will deform, and this deformation will absorb most or all of the force of the collision. Viewed from a conservation of energy perspective, the kinetic energy of the projectile is changed into heat and sound energy, as a result of the deformations and vibrations induced in the struck object. However, these deformations and vibrations cannot occur instantaneously. A high-velocity collision (an impact) does not provide sufficient time for these deformations and vibrations to occur. Thus, the struck material behaves as if it were more brittle than it would otherwise be, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newtons Cradle 00622
The newton (symbol: N) is the unit of force in the International System of Units (SI). Expressed in terms of SI base units, it is 1 kg⋅m/s2, the force that accelerates a mass of one kilogram at one metre per second squared. The unit is named after Isaac Newton in recognition of his work on classical mechanics, specifically his second law of motion. Definition A newton is defined as 1 kg⋅m/s2 (it is a named derived unit defined in terms of the SI base units). One newton is, therefore, the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in the direction of the applied force. The units "metre per second squared" can be understood as measuring a rate of change in velocity per unit of time, i.e. an increase in velocity by one metre per second every second. In 1946, the General Conference on Weights and Measures (CGPM) Resolution 2 standardized the unit of force in the MKS system of units to be the amount needed t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hertzian Contact Stress
Hertzian may refer to: * Hertzian antenna * Hertzian cone, the cone produced when an object passes through a solid, such as a bullet through glass * Hertzian contact stress, localized stresses that develop as two curved surfaces come in contact and deform slightly under imposed loads * Hertzian dipole In radio and telecommunications a dipole antenna or doublet is one of the two simplest and most widely used types of antenna; the other is the monopole. The dipole is any one of a class of antennas producing a radiation pattern approxima ..., defined as a finite oscillating current over an infinitesimal length at a specified position * Hertzian wave, the original name of radio waves * Hertzian wave telegraphy {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballistics
Ballistics is the field of mechanics concerned with the launching, flight behaviour and impact effects of projectiles, especially weapon munitions such as bullets, unguided bombs, rockets and the like; the science or art of designing and accelerating projectiles so as to achieve a desired performance. A ballistic body is a free-moving body with momentum, which can be subject to forces such as those exerted by pressurized gases from a gun barrel or a propelling nozzle, normal force by rifling, and gravity and air drag during flight. A ballistic missile is a missile that is missile guidance, guided only during the relatively brief initial phase of powered flight, with the trajectory subsequently governed by the laws of classical mechanics, in contrast to (for example) a cruise missile, which is aerodynamics, aerodynamically guided in powered flight like a fixed-wing aircraft. History and prehistory The earliest known ballistic projectiles were stones, spears, and the throwing s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Wrench
An impact wrench (also known as an impactor, impact gun, air wrench, air gun, rattle gun, torque gun, windy gun) is a socket wrench power tool designed to deliver high torque output with minimal exertion by the user, by storing energy in a rotating mass, then delivering it suddenly to the output shaft. It was invented by Robert H. Pott of Evansville, Indiana. Compressed air is the most common power source, although electric or hydraulic power is also used, with cordless electric devices becoming increasingly popular since the mid-2000s. Impact wrenches are widely used in many industries, such as automotive repair, heavy equipment maintenance, product assembly, major construction projects, and any other instance where a high torque output is needed. For product assembly, a pulse tool is commonly used, as it features a reactionless tightening while reducing the noise levels the regular impacts suffer from. Pulse tools use oil as a medium to transfer the kinetic energy from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pile Driver
A pile driver is a heavy-duty tool used to drive piles into soil to build piers, bridges, cofferdams, and other "pole" supported structures, and patterns of pilings as part of permanent deep foundations for buildings or other structures. Pilings may be made of wood, solid steel, or tubular steel (often later filled with concrete), and may be driven entirely underwater/underground, or remain partially aboveground as elements of a finished structure. The term "pile driver" is also used to describe members of the construction crew associated with the task,Piles and Pile Foundations. C.Viggiani, A.Mandolini, G.Russo. 296 pag, ISBN 978-0367865443, ISBN 0367865440 also colloquially known as "pile bucks". The most common form of pile driver uses a heavy weight situated between vertical guides placed above a pile. The weight is raised by some motive power (which may include hydraulics, steam, diesel, electrical motor, or manual labor). At its apex the weight is released, impacting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of the processes involved is called tribology, and has a history of more than 2000 years. Friction can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Another important consequence of many types of friction can be wear, which may lead to performance degradation or damage to components. It is known that frictional energy losses account for about 20% of the total energy expenditure of the world. As briefly discussed later, there are many different contributors to the retarding force in friction, ranging from asperity deformation to the generation of charges and changes in local structure. When two bodies in contact move relative to each other, due to these various ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hammer
A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nail (fastener), nails into wood, to shape metal (as with a forge), or to crush Rock (geology), rock. Hammers are used for a wide range of driving, shaping, breaking and non-destructive striking applications. Traditional disciplines include carpentry, blacksmithing, war hammer, warfare, and mallet percussion, percussive musicianship (as with a gong). Hammering is use of a hammer in its strike capacity, as opposed to pry bar, prying with a secondary claw or grappling with a secondary hook. Carpentry and blacksmithing hammers are generally wielded from a stationary stance against a stationary target as gripped and propelled with one arm, in a lengthy downward plane (geometry), planar arc—downward to add kinetic energy to the impact—pivoting mainly around the shoulder and elbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nail (fastener)
In woodworking and construction, a nail is a small object made of metal (or wood, called a tree nail or "trunnel") which is used as a fastener, as a peg to hang something, or sometimes as a decoration. Generally, nails have a sharp point on one end and a flattened head on the other, but headless nails are available. Nails are made in a great variety of forms for specialized purposes. The most common is a ''wire nail''. Other types of nails include ''pins'', ''Thumbtack, tacks'', ''wikt:brad, brads'', ''spikes'', and ''cleat (shoe), cleats.'' Nails are typically driven into the workpiece by a hammer or nail gun. A nail holds materials together by friction in the axial direction and Shear stress, shear strength laterally. The point of the nail is also sometimes bent over or ''clinched'' after driving to prevent pulling out. History The history of the nail is divided roughly into three distinct periods: * Hand-wrought (forged) nail (pre-history until 19th century) * Cut nail (ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Wrench 01
Impact may refer to: * Impact (mechanics), a large force or mechanical shock over a short period of time * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impact event, the collision of a meteoroid, asteroid or comet with Earth * Impact factor, a measure of the citations to a science or social science journal * Impact wrench, a socket wrench power tool capable of high torque Books and magazines * ''Impact'' (novel), a 2010 novel by Douglas Preston *'' Impact Press'', a former Orlando, Florida-based magazine * Impact Magazines, a former UK magazine publisher * ''Impact'' (conservative magazine), a British political magazine * ''Impact'' (British magazine), a British action film magazine * ''Impact'', a French action film magazine spun off from '' Mad Movies'' * ''Impact'' (UNESCO magazine), a former UNESCO quarterly titled ''IMPACT of science on society'' * ''Impact'' (student magazine), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
