Ballistic movement can be defined as muscle contractions that exhibit maximum velocities and accelerations over a very short period of time. They exhibit high firing rates, high force production, and very brief contraction times.
91-503: 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 nails into wood , to shape metal (as with a forge ), or to crush rock . Hammers are used for a wide range of driving, shaping, breaking and non-destructive striking applications. Traditional disciplines include carpentry , blacksmithing , warfare , and percussive musicianship (as with
182-407: A gong ). Hammering is use of a hammer in its strike capacity, as opposed to 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 planar arc—downward to add kinetic energy to the impact—pivoting mainly around
273-491: A magnetized face, to pick up tacks. In the hatchet, the flat hammer head may be secondary to the cutting edge of the tool. The impact between steel hammer heads and the objects being hit can create sparks , which may ignite flammable or explosive gases . These are a hazard in some industries such as underground coal mining (due to the presence of methane gas), or in other hazardous environments such as petroleum refineries and chemical plants . In these environments,
364-425: A resilient material such as rubber for improved grip and to reduce user fatigue. The hammer head may be surfaced with a variety of materials including brass , bronze , wood, plastic, rubber, or leather. Some hammers have interchangeable striking surfaces, which can be selected as needed or replaced when worn out. A large hammer-like tool is a maul (sometimes called a "beetle"), a wood- or rubber-headed hammer
455-513: A "Birth Choice tool": The tool encourages women to consider out-of-hospital settings where appropriate, and the idea of a "toolkit" is used by the International Labour Organization to describe a set of processes applicable to improving global labour relations . A telephone is a communication tool that interfaces between two people engaged in conversation at one level. It also interfaces between each user and
546-497: A 2010 study suggests the hominin species Australopithecus afarensis ate meat by carving animal carcasses with stone implements. This finding pushes back the earliest known use of stone tools among hominins to about 3.4 million years ago. Finds of actual tools date back at least 2.6 million years in Ethiopia . One of the earliest distinguishable stone tool forms is the hand axe . Up until recently, weapons found in digs were
637-583: A ballistic muscle movement can exhibit a muscle coactivation of concurrent agonist and antagonist muscles or the characteristic triphasic agonist/antagonist/agonist muscle activation. Electromyography (EMG) recordings of demonstrate the triphasic muscle activation begins with a brief agonist motor unit activation signal with firing rates of 60 to 120 Hz that may last for 100ms and occurs 50 to 100ms before movement begins. The firing rates of ballistic movements are much higher than that of slow ramp movements (5–15 Hz). The brief agonist muscle contraction
728-464: A bell-shaped velocity profile. The Bayesian Model (see Bayesian network ), which was developed to perform recognition without pose-tracking, explains human ballistic movement as a sequence of movements between objects and the environment. Each movement is independent from precedent and subsequent one, in varying context. Fast single joints movement in humans is controlled by a series of activation of agonist, antagonist and then agonist muscles; this process
819-647: A change in the environment, thereby facilitating one's achievement of a target goal. Anthropologists believe that the use of tools was an important step in the evolution of mankind . Because tools are used extensively by both humans (Homo sapiens) and wild chimpanzees , it is widely assumed that the first routine use of tools took place prior to the divergence between the two ape species. These early tools, however, were likely made of perishable materials such as sticks, or consisted of unmodified stones that cannot be distinguished from other stones as tools. Stone artifacts date back to about 2.5 million years ago. However,
910-469: A cheap tool could be used to occupy the place of a missing mechanical part. A window roller in a car could be replaced with pliers . A transmission shifter or ignition switch would be able to be replaced with a screwdriver. Again, these would be considered tools that are being used for their unintended purposes, substitution as makeshift. Tools such as a rotary tool would be considered the substitution "by-design", or "multi-purpose". This class of tools allows
1001-615: A diverse array of objects and materials, many of which are specifically chosen by certain birds for their unique qualities. Woodpecker finches insert twigs into trees in order to catch or impale larvae. Parrots may use tools to wedge nuts so that they can crack open the outer shell of nuts without launching away the inner contents. Some birds take advantage of human activity, such as carrion crows in Japan, which drop nuts in front of cars to crack them open. Several species of fish use tools to hunt and crack open shellfish, extract food that
SECTION 10
#17327650739631092-446: A handle gave the user better control and less accidents. The hammer became the primary tool used for building, food, and protection. The hammer's archaeological record shows that it may be the oldest tool for which definite evidence exists. A traditional hand-held hammer consists of a separate head and a handle, which can be fastened together by means of a special wedge made for the purpose, or by glue , or both. This two-piece design
1183-532: A localized or isolated manner within certain unique primate cultures , being transmitted and practiced among socially connected primates through cultural learning . Many famous researchers, such as Charles Darwin in his book The Descent of Man , mentioned tool-use in monkeys (such as baboons ). Among other mammals , both wild and captive elephants are known to create tools using their trunks and feet, mainly for swatting flies, scratching, plugging up waterholes that they have dug (to close them up again so
1274-399: A lunging motion, especially against moving targets. Small mallets can be swung from the wrists in a smaller motion permitting a much higher cadence of repeated strikes. Use of hammers and heavy mallets for demolition must adapt the hammer stroke to the location and orientation of the target, which can necessitate a clubbing or golfing motion with a two-handed grip. The modern hammer head
1365-703: A major expansion in their use in Ancient Greece and Ancient Rome with the systematic employment of new energy sources, especially waterwheels . Their use expanded through the Dark Ages with the addition of windmills . Machine tools occasioned a surge in producing new tools in the Industrial Revolution . Pre-industrial machinery was built by various craftsmen— millwrights built water and windmills, carpenters made wooden framing, and smiths and turners made metal parts. Wooden components had
1456-485: A sign of their faith. In American folklore , the hammer of John Henry represents the strength and endurance of a man. A political party in Singapore, Workers' Party of Singapore , based their logo on a hammer to symbolize the party's civic nationalism and social democracy ideology. A variant, well-known symbol with a hammer in it is the hammer and sickle , which was the symbol of the former Soviet Union and
1547-504: A site near Kenya 's Lake Turkana discovered a very large deposit of various shaped stones including those used to strike wood , bone , or other stones to break them apart and shape them. The first hammers were made without handles. Stones attached to sticks with strips of leather or animal sinew were being used as hammers with handles by about 30,000 BCE during the middle of the Paleolithic Stone Age . The addition of
1638-492: A small wooden mallet, is used to symbolize a mandate to preside over a meeting or judicial proceeding, and a graphic image of one is used as a symbol of legislative or judicial decision-making authority. Judah Maccabee was nicknamed "The Hammer", possibly in recognition of his ferocity in battle. The name "Maccabee" may derive from the Aramaic maqqaba . (see Judah Maccabee § Origin of Name "The Hammer" .) The hammer in
1729-408: A steel head with up to 30% recoil. Dead blow hammers use special rubber or steel shot to absorb recoil energy, rather than bouncing the hammer head after impact. The handle of the hammer helps in several ways. It keeps the user's hands away from the point of impact. It provides a broad area that is better-suited for gripping by the hand. Most importantly, it allows the user to maximize the speed of
1820-419: A symbol of mining. In mythology, the gods Thor ( Norse ) and Sucellus ( Celtic and Gallo-Roman ), and the hero Hercules ( Greek ), all had hammers that appear in their lore and carried different meanings. Thor, the god of thunder and lightning, wields a hammer named Mjölnir . Many artifacts of decorative hammers have been found, leading modern practitioners of this religion to often wear reproductions as
1911-474: A tapping movement to the same target area. It has been suggested that the cognitive demands for pre-planning, sequencing and accurate timing associated with the related ballistic movements of throwing , clubbing, and hammering precipitated aspects of brain evolution in early hominids . The use of simple hammers dates to around 3.3 million years ago according to the 2012 find made by Sonia Harmand and Jason Lewis of Stony Brook University , who while excavating
SECTION 20
#17327650739632002-410: A thermally independent ballistic movement is tongue projection in chameleons . It was discovered that veiled chameleons (Chamaeleo calyptratus) were able to perform this high-performance tongue projection, and successful prey capture, across a wide range of temperatures (15 °C–35 °C). Anderson and Deban also found a contrast between thermal dependence of tongue projection and retraction (which
2093-430: A variety of non-sparking metal tools are used, primarily made of aluminium or beryllium copper . In recent years, the handles have been made of durable plastic or rubber, though wood is still widely used because of its shock-absorbing qualities and repairability. Mechanically powered hammers often look quite different from the hand tools, but nevertheless, most of them work on the same principle. They include: A hammer
2184-455: Is "makeshift" when human ingenuity comes into play and a tool is used for an unintended purpose, such as using a long screwdriver to separate a cars control arm from a ball joint, instead of using a tuning fork. In many cases, the designed secondary functions of tools are not widely known. For example, many wood-cutting hand saws integrate a square by incorporating a specially-shaped handle, that allows 90° and 45° angles to be marked by aligning
2275-432: Is a mallet , and a hammer-like tool with a cutting blade is usually called a hatchet . The essential part of a hammer is the head, a compact solid mass that is able to deliver a blow to the intended target without itself deforming. The impacting surface of the tool is usually flat or slightly rounded; the opposite end of the impacting mass may have a ball shape, as in the ball-peen hammer . Some upholstery hammers have
2366-518: Is a motto of some importance for workers who cannot practically carry every specialized tool to the location of every work task, such as a carpenter who does not necessarily work in a shop all day and needs to do jobs in a customer's house. Tool substitution may be divided broadly into two classes: substitution "by-design", or "multi-purpose", and substitution as makeshift. Substitution "by-design" would be tools that are designed specifically to accomplish multiple tasks using only that one tool. Substitution
2457-428: Is a simple force amplifier that works by converting mechanical work into kinetic energy and back. In the swing that precedes each blow, the hammer head stores a certain amount of kinetic energy—equal to the length D of the swing times the force f produced by the muscles of the arm and by gravity . When the hammer strikes, the head is stopped by an opposite force coming from the target, equal and opposite to
2548-527: Is also a good conductor of heat, making it unsuitable for contact with bare skin in frigid conditions. Modern hammers with steel shafts are almost invariably clad with a synthetic polymer to improve grip, dampen vibration , and to provide thermal insulation . A suitably contoured handle is also an important aid in providing a secure grip during heavy use. Traditional wooden handles were reasonably good in all regards, but lack strength and durability compared to steel, and there are safety issues with wooden handles if
2639-399: Is applied to these elastic elements over a relatively slow period of time, and is released very rapidly. Higher power output is produced because the energy is released in a much shorter amount of time than it is stored. In this sense the power of the muscles is actually amplified. When energy is produced by muscle contraction, stored in a tendon, then released to increase mechanical energy of
2730-491: Is considered hazardous due to the risk of the head becoming detached from the handle while being swung becoming a dangerous uncontrolled projectile. Wooden handles can often be replaced when worn or damaged; specialized kits are available covering a range of handle sizes and designs, plus special wedges and spacers for secure attachment. Some hammers are one-piece designs made mostly of a single material. A one-piece metallic hammer may optionally have its handle coated or wrapped in
2821-468: Is controlled by an elastic recoil mechanism. The orientation of the muscle fibers is significant because it is what allows ballistic movements to be possible. In chameleons, the muscle fibers used for ballistic tongue movements were found to be in a spiral orientation, with an equal amount of fibers oriented clockwise and anti-clockwise to prevent torsional movement of the tongue during projection. The internal fiber angles are approximately 45 degrees, which
Hammer - Misplaced Pages Continue
2912-450: Is for example a combination of a measuring tool (the clock) and a perception tool (the alarm). This enables the alarm-clock to be a tool that falls outside of all the categories mentioned above. There is some debate on whether to consider protective gear items as tools, because they do not directly help perform work, just protect the worker like ordinary clothing. They do meet the general definition of tools and in many cases are necessary for
3003-490: Is made with stone arches and lined with waterproof concrete. The earliest evidence of water wheels and watermills date back to the ancient Near East in the 4th century BC, specifically in the Persian Empire before 350 BC, in the regions of Mesopotamia (Iraq) and Persia (Iran). This pioneering use of water power constituted perhaps the first use of mechanical energy . Mechanical devices experienced
3094-419: Is not elastically-powered). This further supports the hypothesis that the elastic recoil mechanism is responsible for the decreased thermal dependence of ballistic tongue projection. In trap-jaw ants ( Odontomachus bauri) ballistic movement can be seen in their extremely rapid mandible strikes. The trap-jaw ants mandible has an average closing speed of 38.4 m/s and can produce forces that are 371-504 times
3185-412: Is not needed to produce a force strong enough to bend steel, or crack the hardest stone. The amount of energy delivered to the target by the hammer-blow is equivalent to one half the mass of the head times the square of the head's speed at the time of impact ( E = m v 2 2 ) {\displaystyle (E={mv^{2} \over 2})} . While the energy delivered to
3276-487: Is often used to combine a dense metallic striking head with a non-metallic mechanical-shock-absorbing handle (to reduce user fatigue from repeated strikes). If wood is used for the handle, it is often hickory or ash , which are tough and long-lasting materials that can dissipate shock waves from the hammer head. Rigid fiberglass resin may be used for the handle; this material does not absorb water or decay but does not dissipate shock as well as wood. A loose hammer head
3367-545: Is out of reach, or clear an area for nesting. Among cephalopods (and perhaps uniquely or to an extent unobserved among invertebrates ), octopuses are known to use tools relatively frequently, such as gathering coconut shells to create a shelter or using rocks to create barriers. By extension, concepts which support systematic or investigative thought are often referred to as "tools", for example Vanessa Dye refers to "tools of reflection" and "tools to help sharpen your professional practice" for trainee teachers, illustrating
3458-466: Is strongly linked to communism and early socialism . The hammer in this symbol represents the industrial working class (and the sickle represents the agricultural working class). The hammer is used in some coats of arms in former socialist countries like East Germany . Similarly, the Hammer and Sword symbolizes Strasserism , a strand of Nazism seeking to appeal to the working class. Another variant of
3549-537: Is the SARA, which is located near the back of the head. The SARA remains active until the tongue makes contact with the prey. Next, the posterior SARP, located further back on the medial and lateral sides of the salamander is activated. Then the middle SARP is activated and the anterior SARP is the last to be activated. The time between activation shortens and duration of activation increases with increasing prey distance. Ballistic tongues have evolved two times previously in
3640-421: Is the theoretical optimum to create an equal strain throughout the accelerator muscles. In salamanders of the genus Hydromantes , the pattern of muscle activation has been mapped. The main muscles used for ballistic tongue movements in these salamanders are the subarcualis rectus (SAR) muscles. These SAR muscles can be further divided into anterior (SARA) and posterior (SARP). The first muscle to be activated
3731-429: Is thus followed by antagonist muscle unit activation. The degree of antagonist muscle unit activation is dependent on the task at hand unlike the first agonist muscle activation which is independent to environmental stimuli. The function of the antagonist muscle contraction is believed to control the amplitude and timing of ballistic movements. Antagonist muscle contraction may serve to prevent injury to joints by preventing
Hammer - Misplaced Pages Continue
3822-498: Is trying to flee from a predator it will strike at the substrate and propel itself vertically into the air. In crickets ( Acheta domesticus ) ballistic movements can be seen in the way they jump. The kicks that propel the cricket occur over a period of only 2-6ms, but during the 18-40ms prior to the kick the potential energy required is built up by the co-contraction of the antagonistic extensor and flexor tibiae. The crickets can also use these same ballistic movements for swimming. In
3913-703: Is typically made of steel which has been heat treated for hardness, and the handle (also known as a haft or helve ) is typically made of wood or plastic . Ubiquitous in framing , the claw hammer has a "claw" to pull nails out of wood, and is commonly found in an inventory of household tools in North America . Other types of hammers vary in shape, size, and structure, depending on their purposes. Hammers used in many trades include sledgehammers , mallets , and ball-peen hammers . Although most hammers are hand tools, powered hammers , such as steam hammers and trip hammers , are used to deliver forces beyond
4004-426: The Industrial Revolution marking an inflection point in the use of tools. The introduction of widespread automation in the 19th and 20th centuries allowed tools to operate with minimal human supervision, further increasing the productivity of human labor . By extension, concepts that support systematic or investigative thought are often referred to as "tools" or "toolkits". While a common-sense understanding of
4095-646: The Swiss Army knife represents one of the earliest examples. Other tools have a primary purpose but also incorporate other functionality – for example, lineman's pliers incorporate a gripper and cutter and are often used as a hammer; and some hand saws incorporate a square in the right-angle between the blade's dull edge and the saw's handle. This would also be the category of "multi-purpose" tools, since they are also multiple tools in one (multi-use and multi-purpose can be used interchangeably – compare hand axe ). These types of tools were specifically made to catch
4186-422: The acceleration during the hammer stroke and increases the energy delivered with each blow. If hammering upwards, gravity reduces the acceleration during the hammer stroke and therefore reduces the energy delivered with each blow. Some hammering methods, such as traditional mechanical pile drivers , rely entirely on gravity for acceleration on the down stroke. A hammer may cause significant injury if it strikes
4277-509: The Hemidactyliini and Bolitoglossini genera. The exact mechanisms of tongue projection vary slightly throughout the taxa, but the resulting projections have remained relatively constant. Frogs do not have a specialized muscular structure for tongue projection. They are able to bypass this issue by using very rapid jaw movement to project the tongue forward. Present in all frogs are the two mandibular muscles that are used to control
4368-582: The actual movement. One prime example of this is tongue projection in salamanders . This decoupling of muscle work from body/limb work is a major benefit of elastic energy storage mechanisms. Another benefit resulting from this decoupling is decreased thermal dependence of ballistic movement. Deban and Lappin analyzed the prey capture behavior of toads (Bufo terrestris), which involves two types of movement: elastically powered, ballistic movement (mouth opening and tongue projection) and muscle-powered movement (tongue retraction and mouth closing). The toad feeding
4459-449: The appropriate part of the handle with an edge, and scribing along the back edge of the saw. The latter is illustrated by the saying "All tools can be used as hammers". Nearly all tools can be used to function as a hammer, even though few tools are intentionally designed for it and even fewer work as well as the original. Tools are often used to substitute for many mechanical apparatuses, especially in older mechanical devices. In many cases
4550-421: The body (or body segment), muscle power is amplified. It is important to note, however, that the term power ‘amplification’ may be deceptive. In animals, elastic mechanisms never add energy to the system; they amplify power in the sense that the energy is released more rapidly than it is stored. Ballistic systems are capable of power outputs that are significantly greater than that of the muscles associated with
4641-415: The body. Both manual and powered hammers can cause peripheral neuropathy or a variety of other ailments when used improperly. Awkward handles can cause repetitive stress injury (RSI) to hand and arm joints, and uncontrolled shock waves from repeated impacts can injure nerves and the skeleton. Additionally, striking metal objects with a hammer may produce small metallic projectiles which can become lodged in
SECTION 50
#17327650739634732-436: The capacity of the human arm. There are over 40 different types of hammers that have many different types of uses. For hand hammers, the grip of the shaft is an important consideration. Many forms of hammering by hand are heavy work, and perspiration can lead to slippage from the hand, turning a hammer into a dangerous or destructive uncontrolled projectile. Steel is highly elastic and transmits shock and vibration ; steel
4823-542: The communication network at another level. It is in the domain of media and communications technology that a counter-intuitive aspect of our relationships with our tools first began to gain popular recognition. John M. Culkin famously said, "We shape our tools and thereafter our tools shape us". One set of scholars expanded on this to say: "Humans create inspiring and empowering technologies but also are influenced, augmented, manipulated, and even imprisoned by technology". Ballistic movement The muscle contraction of
4914-409: The completion of the work. Personal protective equipment includes such items as gloves , safety glasses , ear defenders and biohazard suits. Often, by design or coincidence, a tool may share key functional attributes with one or more other tools. In this case, some tools can substitute for other tools, either as a makeshift solution or as a matter of practical efficiency. "One tool does it all"
5005-459: The cone snail ( Conus catus ) ballistic movement can be seen in the way that it fires is harpoon-like radular tooth into its prey. After the cone snail’s proboscis comes in contact with its prey the tooth is ejected 240-295 ms later. It is believed that the propulsion of the tooth is accomplished by pressurizing the fluid space behind the tooth. In Salamanders , Toads , and Chameleons ballistic movement can be seen in their tongue projection which
5096-459: The connection between physical and conceptual tools by quoting the French scientist Claude Bernaud : we must change [our ideas] when they have served their purpose, as we change a blunt lancet that we have used long enough. Similarly, a decision-making process "developed to help women and their partners make confident and informed decisions when planning where to give birth" is described as
5187-549: The definition of what constitutes a tool and therefore which behaviours can be considered true examples of tool use. Observation has confirmed that a number of species can use tools including monkeys , apes , elephants , several birds, and sea otters . Now the unique relationship of humans with tools is considered to be that we are the only species that uses tools to make other tools. Primates are well known for using tools for hunting or gathering food and water, cover for rain, and self-defense. Chimpanzees have often been
5278-407: The development of several machine tools . They have their origins in the tools developed in the 18th century by makers of clocks and watches and scientific instrument makers to enable them to batch-produce small mechanisms. Before the advent of machine tools, metal was worked manually using the basic hand tools of hammers, files, scrapers, saws, and chisels. Consequently, the use of metal machine parts
5369-636: The disadvantage of changing dimensions with temperature and humidity, and the various joints tended to rack (work loose) over time. As the Industrial Revolution progressed, machines with metal parts and frames became more common. Other important uses of metal parts were in firearms and threaded fasteners, such as machine screws, bolts, and nuts. There was also the need for precision in making parts. Precision would allow better working machinery, interchangeability of parts, and standardization of threaded fasteners. The demand for metal parts led to
5460-473: The early centuries of recorded history, but archaeological evidence can provide dates of development and use. Several of the six classic simple machines ( wheel and axle , lever , pulley , inclined plane , wedge , and screw ) were invented in Mesopotamia . The wheel and axle mechanism first appeared with the potter's wheel , invented in what is now Iraq during the 5th millennium BC. This led to
5551-410: The effect of the hammer on the user. Handles made of shock-absorbing materials or varying angles attempt to make it easier for the user to continue to wield this age-old device, even as nail guns and other powered drivers encroach on its traditional field of use. As hammers must be used in many circumstances, where the position of the person using them cannot be taken for granted, trade-offs are made for
SECTION 60
#17327650739635642-444: The eye of many different craftsman who traveled to do their work. To these workers these types of tools were revolutionary because they were one tool or one device that could do several different things. With this new revolution of tools, the traveling craftsman would not have to carry so many tools with them to job sites, in that their space would be limited to the vehicle or to the beast of burden they were driving. Multi-use tools solve
5733-470: The eye. It is therefore recommended to wear safety glasses . A war hammer is a late medieval weapon of war intended for close combat action. The hammer, being one of the most used tools by man , has been used very much in symbols such as flags and heraldry . In the Middle Ages, it was used often in blacksmith guild logos, as well as in many family symbols. The hammer and pick are used as
5824-422: The force applied by the head to the target. If the target is a hard and heavy object, or if it is resting on some sort of anvil , the head can travel only a very short distance d before stopping. Since the stopping force F times that distance must be equal to the head's kinetic energy, it follows that F is much greater than the original driving force f —roughly, by a factor D / d . In this way, great strength
5915-415: The hammer to its target at full speed. Most designs are a compromise between practicality and energy efficiency . With too long a handle, the hammer is inefficient because it delivers force to the wrong place, off-target. With too short a handle, the hammer is inefficient because it does not deliver enough force, requiring more blows to complete a given task. Modifications have also been made with respect to
6006-505: The head becomes loose on the shaft. The high elasticity of the steel head is important in energy transfer, especially when used in conjunction with an equally elastic anvil . In terms of human physiology , many uses of the hammer involve coordinated ballistic movements under intense muscular forces which must be planned in advance at the neuromuscular level , as they occur too rapidly for conscious adjustment in flight. For this reason, accurate striking at speed requires more practice than
6097-408: The head on each blow. The primary constraint on additional handle length is the lack of space to swing the hammer. This is why sledgehammers, largely used in open spaces, can have handles that are much longer than a standard carpenter's hammer. The second most important constraint is more subtle. Even without considering the effects of fatigue, the longer the handle, the harder it is to guide the head of
6188-467: The invention of the wheeled vehicle in Mesopotamia during the early 4th millennium BC. The lever was used in the shadoof water-lifting device, the first crane machine, which appeared in Mesopotamia c. 3000 BC , and then in ancient Egyptian technology c. 2000 BC . The earliest evidence of pulleys date back to Mesopotamia in the early 2nd millennium BC. The screw ,
6279-556: The jaw and, therefore, tongue projection. The m. genioglossus is used to protract the tongue and the m.hyoglossus is the tongue retractor. Both of these muscles have longitudinally oriented fibers, which is in contrast to the spiral oriented fibers of the chameleon. In human, ballistic movements involve spontaneous propulsion of the limbs. This can be seen in daily routines such as reach and strike reactions, which are atomic by nature. Pointing gestures and placing an object are reach reactions; they have low acceleration and deceleration. On
6370-490: The last of the simple machines to be invented, first appeared in Mesopotamia during the Neo-Assyrian period (911–609 BC). The Assyrian King Sennacherib (704–681 BC) claims to have invented automatic sluices and to have been the first to use water screw pumps , of up to 30 tons weight, which were cast using two-part clay molds rather than by the ' lost wax ' process. The Jerwan Aqueduct ( c. 688 BC)
6461-399: The limb from overextending itself and also function to control the distance and time the limb is being moved. Experiments involving ballistic movement of small amplitudes show a marked increase in antagonist muscle activation and experiments where distance moved is not controlled antagonist muscle activation was decreased or absent. The second agonist muscle activation is suggested to terminate
6552-483: The meaning of tool is widespread, several formal definitions have been proposed. In 1981, Benjamin Beck published a widely used definition of tool use. This has been modified to: The external employment of an unattached or manipulable attached environmental object to alter more efficiently the form, position, or condition of another object, another organism, or the user itself, when the user holds and directly manipulates
6643-426: The negative acceleration of the antagonist muscle contraction and thus the ballistic movement. Ballistic movements are often powered through elastic energy storage and subsequent recovery mechanisms. The power required to produce the extremely rapid velocities of ballistic movements is made possible through muscle work being stored in elastic elements (such as tendons , aponeuroses , or even muscle). Muscle work
6734-480: The object of study in regard to their usage of tools, most famously by Jane Goodall ; these animals are closely related to humans. Wild tool-use in other primates, especially among apes and monkeys , is considered relatively common, though its full extent remains poorly documented, as many primates in the wild are mainly only observed distantly or briefly when in their natural environments and living without human influence. Some novel tool-use by primates may arise in
6825-412: The only tools of "early man" that were studied and given importance. Now, more tools are recognized as culturally and historically relevant. As well as hunting, other activities required tools such as preparing food, "...nutting, leatherworking , grain harvesting and woodworking..." Included in this group are "flake stone tools". Tools are the most important items that the ancient humans used to climb to
6916-446: The other hand, punching and throwing are strike reactions; they are characterized by high acceleration and deceleration. These movements have highly variable target locations, and they are referred to as “ballistic” in kinesiology . During ballistic movement an initial impulse is needed to accelerate the limb (hand/foot) toward the target, then a decelerating impulse act as a brake to stop the movement. These movements are characterized by
7007-499: The preparation of food , hunting , the manufacture of weapons , and the working of materials to produce clothing and useful artifacts and crafts such as pottery , along with the construction of housing , businesses , infrastructure , and transportation . The development of metalworking made additional types of tools possible. Harnessing energy sources , such as animal power , wind , or steam , allowed increasingly complex tools to produce an even larger range of items, with
7098-427: The problem of having to deal with many different tools. Tool use by animals is a phenomenon in which an animal uses any kind of tool in order to achieve a goal such as acquiring food and water, grooming , defense, communication , recreation or construction . Originally thought to be a skill possessed only by humans , some tool use requires a sophisticated level of cognition. There is considerable discussion about
7189-455: The sake of practicality. In areas where one has plenty of room, a long handle with a heavy head (like a sledgehammer) can deliver the maximum amount of energy to the target. It is not practical to use such a large hammer for all tasks, however, and thus the overall design has been modified repeatedly to achieve the optimum utility in a wide variety of situations. Gravity exerts a force on the hammer head. If hammering downwards, gravity increases
7280-549: The shells of prey, as well as for scratching. Corvids (such as crows , ravens and rooks ) are well known for their large brains (among birds ) and tool use. New Caledonian crows are among the only animals that create their own tools. They mainly manufacture probes out of twigs and wood (and sometimes metal wire) to catch or impale larvae . Tool use in some birds may be best exemplified in nest intricacy. Tailorbirds manufacture 'pouches' to make their nests in. Some birds, such as weaver birds , build complex nests utilizing
7371-424: The shoulder and elbow, with a small but brisk wrist rotation shortly before impact; for extreme impact, concurrent motions of the torso and knee can lower the shoulder joint during the swing to further increase the length of the swing arc (but this is tiring). War hammers are often wielded in non-vertical planes of motion, with a far greater share of energy input provided from the legs and hips, which can also include
7462-600: The song " If I Had a Hammer " represents a relentless message of justice broadcast across the land. The song became a symbol of the civil rights movement . Tool A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools , only human beings, whose use of stone tools dates back hundreds of millennia, have been observed using tools to make other tools. Early human tools, made of such materials as stone , bone , and wood , were used for
7553-522: The symbol was used for the North Korean party, Workers' Party of Korea , incorporated with an ink brush on the middle, which symbolizes both Juche and Songun ideologies. In Pink Floyd – The Wall , two hammers crossed are used as a symbol for the fascist takeover of the concert during " In the Flesh ". This also has the meaning of the hammer beating down any "nails" that stick out. The gavel ,
7644-428: The target increases linearly with mass, it increases quadratically with the speed (see the effect of the handle, below). High tech titanium heads are lighter and allow for longer handles, thus increasing velocity and delivering the same energy with less arm fatigue than that of a heavier steel head hammer. A titanium head has about 3% recoil energy and can result in greater efficiency and less fatigue when compared to
7735-476: The tool during or prior to use and is responsible for the proper and effective orientation of the tool. Other, briefer definitions have been proposed: An object carried or maintained for future use. The use of physical objects other than the animal's own body or appendages as a means to extend the physical influence realized by the animal. An object that has been modified to fit a purpose ... [or] An inanimate object that one uses or modifies in some way to cause
7826-530: The top of the food chain ; by inventing tools, they were able to accomplish tasks that human bodies could not, such as using a spear or bow to kill prey , since their teeth were not sharp enough to pierce many animals' skins. "Man the hunter" as the catalyst for Hominin change has been questioned. Based on marks on the bones at archaeological sites, it is now more evident that pre-humans were scavenging off of other predators' carcasses rather than killing their own food. Many tools were made in prehistory or in
7917-402: The use of one tool that has at least two different capabilities. "Multi-purpose" tools are basically multiple tools in one device/tool. Tools such as this are often power tools that come with many different attachments like a rotary tool does, so one could say that a power drill is a "multi-purpose" tool. A multi-tool is a hand tool that incorporates several tools into a single, portable device;
8008-524: The water does not evaporate), and reaching food that is out of reach. Many other social mammals particularly have been observed engaging in tool-use. A group of dolphins in Shark Bay uses sea sponges to protect their beaks while foraging. Sea otters will use rocks or other hard objects to dislodge food (such as abalone ) and break open shellfish . Many or most mammals of the order Carnivora have been observed using tools, often to trap or break open
8099-401: The weight of the ant. The ants use these extremely powerful mandible strikes in several novel ways. When the ant attacks a larger animal it will strike the animal and at the same time use the force from the strike to propel itself away from the animal. When facing prey of similar size such as another ant the strike actually results in both animals being propelled away from each other. When the ant
8190-491: Was kept to a minimum. Hand methods of production were very laborious and costly and precision was difficult to achieve. With their inherent precision, machine tools enabled the economical production of interchangeable parts . Examples of machine tools include: Advocates of nanotechnology expect a similar surge as tools become microscopic in size. One can classify tools according to their basic functions: Some tools may be combinations of other tools. An alarm-clock
8281-507: Was observed across a range of temperatures (11–35 °C), and the kinematic, dynamic, and electromyographic variables were measured and analyzed. Over the 11–35 °C temperature range, the ballistic movements had Q 10 values very close to 1 (Q 10 = 0.99–1.25), signifying thermal independence and supporting the main hypothesis. The muscle-powered movements had a higher temperature coefficient (Q 10 = 1.77–2.26), signifying thermal dependence. Another example of
#962037