99-469: Wadi ( Arabic : وَادِي , romanized : wādī , alternatively wād ; Arabic : وَاد , Maghrebi Arabic oued , Hebrew : וָאדִי , romanized : vadi , lit. 'wadi') is the Arabic term traditionally referring to a river valley . In some instances, it may refer to a wet ( ephemeral ) riverbed that contains water only when heavy rain occurs. Arroyo ( Spanish )
198-496: A ⋅ x ) {\displaystyle \therefore v^{2}=u^{2}+2({\boldsymbol {a}}\cdot {\boldsymbol {x}})} where v = | v | etc. The above equations are valid for both Newtonian mechanics and special relativity . Where Newtonian mechanics and special relativity differ is in how different observers would describe the same situation. In particular, in Newtonian mechanics, all observers agree on
297-605: A ) ⋅ x = ( 2 a ) ⋅ ( u t + 1 2 a t 2 ) = 2 t ( a ⋅ u ) + a 2 t 2 = v 2 − u 2 {\displaystyle (2{\boldsymbol {a}})\cdot {\boldsymbol {x}}=(2{\boldsymbol {a}})\cdot ({\boldsymbol {u}}t+{\tfrac {1}{2}}{\boldsymbol {a}}t^{2})=2t({\boldsymbol {a}}\cdot {\boldsymbol {u}})+a^{2}t^{2}=v^{2}-u^{2}} ∴ v 2 = u 2 + 2 (
396-447: A = d v d t . {\displaystyle {\boldsymbol {a}}={\frac {d{\boldsymbol {v}}}{dt}}.} From there, velocity is expressed as the area under an a ( t ) acceleration vs. time graph. As above, this is done using the concept of the integral: v = ∫ a d t . {\displaystyle {\boldsymbol {v}}=\int {\boldsymbol {a}}\ dt.} In
495-522: A collection of related dialects that constitute the precursor of Arabic, first emerged during the Iron Age . Previously, the earliest attestation of Old Arabic was thought to be a single 1st century CE inscription in Sabaic script at Qaryat al-Faw , in southern present-day Saudi Arabia. However, this inscription does not participate in several of the key innovations of the Arabic language group, such as
594-417: A constant 20 kilometres per hour in a circular path has a constant speed, but does not have a constant velocity because its direction changes. Hence, the car is considered to be undergoing an acceleration. Since the derivative of the position with respect to time gives the change in position (in metres ) divided by the change in time (in seconds ), velocity is measured in metres per second (m/s). Velocity
693-435: A corpus of poetic texts, in addition to Qur'an usage and Bedouin informants whom he considered to be reliable speakers of the ʿarabiyya . Arabic spread with the spread of Islam . Following the early Muslim conquests , Arabic gained vocabulary from Middle Persian and Turkish . In the early Abbasid period , many Classical Greek terms entered Arabic through translations carried out at Baghdad's House of Wisdom . By
792-1081: A dialect of Arabic and written in the Latin alphabet . The Balkan languages, including Albanian, Greek , Serbo-Croatian, and Bulgarian , have also acquired many words of Arabic origin, mainly through direct contact with Ottoman Turkish . Arabic has influenced languages across the globe throughout its history, especially languages where Islam is the predominant religion and in countries that were conquered by Muslims. The most markedly influenced languages are Persian , Turkish , Hindustani ( Hindi and Urdu ), Kashmiri , Kurdish , Bosnian , Kazakh , Bengali , Malay ( Indonesian and Malaysian ), Maldivian , Pashto , Punjabi , Albanian , Armenian , Azerbaijani , Sicilian, Spanish, Greek, Bulgarian, Tagalog , Sindhi , Odia , Hebrew and African languages such as Hausa , Amharic , Tigrinya , Somali , Tamazight , and Swahili . Conversely, Arabic has borrowed some words (mostly nouns) from other languages, including its sister-language Aramaic, Persian, Greek, and Latin and to
891-487: A lesser extent and more recently from Turkish, English, French, and Italian. Arabic is spoken by as many as 380 million speakers, both native and non-native, in the Arab world, making it the fifth most spoken language in the world, and the fourth most used language on the internet in terms of users. It also serves as the liturgical language of more than 2 billion Muslims . In 2011, Bloomberg Businessweek ranked Arabic
990-690: A millennium before the modern period . Early lexicographers ( لُغَوِيُّون lughawiyyūn ) sought to explain words in the Quran that were unfamiliar or had a particular contextual meaning, and to identify words of non-Arabic origin that appear in the Quran. They gathered shawāhid ( شَوَاهِد 'instances of attested usage') from poetry and the speech of the Arabs—particularly the Bedouin ʾaʿrāb [ ar ] ( أَعْراب ) who were perceived to speak
1089-594: A result, many European languages have borrowed words from it. Arabic influence, mainly in vocabulary, is seen in European languages (mainly Spanish and to a lesser extent Portuguese , Catalan , and Sicilian ) owing to the proximity of Europe and the long-lasting Arabic cultural and linguistic presence, mainly in Southern Iberia, during the Al-Andalus era. Maltese is a Semitic language developed from
SECTION 10
#17327662157561188-491: A result. Wadis tend to be associated with centers of human population because sub-surface water is sometimes available in them. Nomadic and pastoral desert peoples will rely on seasonal vegetation found in wadis, even in regions as dry as the Sahara , as they travel in complex transhumance routes. The centrality of wadis to water – and human life – in desert environments gave birth to the distinct sub-field of wadi hydrology in
1287-462: A script derived from ASA attest to a language known as Hasaitic . On the northwestern frontier of Arabia, various languages known to scholars as Thamudic B , Thamudic D, Safaitic , and Hismaic are attested. The last two share important isoglosses with later forms of Arabic, leading scholars to theorize that Safaitic and Hismaic are early forms of Arabic and that they should be considered Old Arabic . Linguists generally believe that "Old Arabic",
1386-470: A single language, despite mutual incomprehensibility among differing spoken versions. From a linguistic standpoint, it is often said that the various spoken varieties of Arabic differ among each other collectively about as much as the Romance languages . This is an apt comparison in a number of ways. The period of divergence from a single spoken form is similar—perhaps 1500 years for Arabic, 2000 years for
1485-588: A two-dimensional system, where there is an x-axis and a y-axis, corresponding velocity components are defined as v x = d x / d t , {\displaystyle v_{x}=dx/dt,} v y = d y / d t . {\displaystyle v_{y}=dy/dt.} The two-dimensional velocity vector is then defined as v =< v x , v y > {\displaystyle {\textbf {v}}=<v_{x},v_{y}>} . The magnitude of this vector represents speed and
1584-507: A type of Arabic. Cypriot Arabic is recognized as a minority language in Cyprus. The sociolinguistic situation of Arabic in modern times provides a prime example of the linguistic phenomenon of diglossia , which is the normal use of two separate varieties of the same language, usually in different social situations. Tawleed is the process of giving a new shade of meaning to an old classical word. For example, al-hatif lexicographically means
1683-507: A variety of regional vernacular Arabic dialects , which are not necessarily mutually intelligible. Classical Arabic is the language found in the Quran , used from the period of Pre-Islamic Arabia to that of the Abbasid Caliphate . Classical Arabic is prescriptive, according to the syntactic and grammatical norms laid down by classical grammarians (such as Sibawayh ) and the vocabulary defined in classical dictionaries (such as
1782-402: A velocity vector, denotes only how fast an object is moving, while velocity indicates both an object's speed and direction. To have a constant velocity , an object must have a constant speed in a constant direction. Constant direction constrains the object to motion in a straight path thus, a constant velocity means motion in a straight line at a constant speed. For example, a car moving at
1881-709: A wide range of sedimentary structures, including ripples and common plane beds. Gravels commonly display imbrications , and mud drapes show desiccation cracks. Wind activity also generates sedimentary structures, including large-scale cross-stratification and wedge-shaped cross-sets. A typical wadi sequence consists of alternating units of wind and water sediments; each unit ranging from about 10–30 cm (4–12 in). Sediment laid by water shows complete fining upward sequence. Gravels show imbrication. Wind deposits are cross-stratified and covered with mud-cracked deposits. Some horizontal loess may also be present. Modern English usage differentiates wadis from canyons or washes by
1980-476: A wider audience." In the wake of the industrial revolution and European hegemony and colonialism , pioneering Arabic presses, such as the Amiri Press established by Muhammad Ali (1819), dramatically changed the diffusion and consumption of Arabic literature and publications. Rifa'a al-Tahtawi proposed the establishment of Madrasat al-Alsun in 1836 and led a translation campaign that highlighted
2079-737: Is a Central Semitic language of the Afroasiatic language family spoken primarily in the Arab world . The ISO assigns language codes to 32 varieties of Arabic , including its standard form of Literary Arabic, known as Modern Standard Arabic , which is derived from Classical Arabic . This distinction exists primarily among Western linguists; Arabic speakers themselves generally do not distinguish between Modern Standard Arabic and Classical Arabic, but rather refer to both as al-ʿarabiyyatu l-fuṣḥā ( اَلعَرَبِيَّةُ ٱلْفُصْحَىٰ "the eloquent Arabic") or simply al-fuṣḥā ( اَلْفُصْحَىٰ ). Arabic
SECTION 20
#17327662157562178-468: Is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. The drag force, F D {\displaystyle F_{D}} , is dependent on the square of velocity and is given as F D = 1 2 ρ v 2 C D A {\displaystyle F_{D}\,=\,{\tfrac {1}{2}}\,\rho \,v^{2}\,C_{D}\,A} where Escape velocity
2277-590: Is a minimum level of comprehension between all Arabic dialects, this level can increase or decrease based on geographic proximity: for example, Levantine and Gulf speakers understand each other much better than they do speakers from the Maghreb. The issue of diglossia between spoken and written language is a complicating factor: A single written form, differing sharply from any of the spoken varieties learned natively, unites several sometimes divergent spoken forms. For political reasons, Arabs mostly assert that they all speak
2376-559: Is a sister language rather than their direct ancestor. Arabia had a wide variety of Semitic languages in antiquity. The term "Arab" was initially used to describe those living in the Arabian Peninsula , as perceived by geographers from ancient Greece . In the southwest, various Central Semitic languages both belonging to and outside the Ancient South Arabian family (e.g. Southern Thamudic) were spoken. It
2475-417: Is always less than or equal to the average speed of an object. This can be seen by realizing that while distance is always strictly increasing, displacement can increase or decrease in magnitude as well as change direction. In terms of a displacement-time ( x vs. t ) graph, the instantaneous velocity (or, simply, velocity) can be thought of as the slope of the tangent line to the curve at any point , and
2574-478: Is believed that the ancestors of the Modern South Arabian languages (non-Central Semitic languages) were spoken in southern Arabia at this time. To the north, in the oases of northern Hejaz , Dadanitic and Taymanitic held some prestige as inscriptional languages. In Najd and parts of western Arabia, a language known to scholars as Thamudic C is attested. In eastern Arabia, inscriptions in
2673-408: Is credited with establishing the rules of Arabic prosody . Al-Jahiz (776–868) proposed to Al-Akhfash al-Akbar an overhaul of the grammar of Arabic, but it would not come to pass for two centuries. The standardization of Arabic reached completion around the end of the 8th century. The first comprehensive description of the ʿarabiyya "Arabic", Sībawayhi's al - Kitāb , is based first of all upon
2772-472: Is credited with standardizing Arabic grammar , or an-naḥw ( النَّحو "the way" ), and pioneering a system of diacritics to differentiate consonants ( نقط الإعجام nuqaṭu‿l-i'jām "pointing for non-Arabs") and indicate vocalization ( التشكيل at-tashkīl ). Al-Khalil ibn Ahmad al-Farahidi (718–786) compiled the first Arabic dictionary, Kitāb al-'Ayn ( كتاب العين "The Book of the Letter ع "), and
2871-720: Is defined as v =< v x , v y , v z > {\displaystyle {\textbf {v}}=<v_{x},v_{y},v_{z}>} with its magnitude also representing speed and being determined by | v | = v x 2 + v y 2 + v z 2 . {\displaystyle |v|={\sqrt {v_{x}^{2}+v_{y}^{2}+v_{z}^{2}}}.} While some textbooks use subscript notation to define Cartesian components of velocity, others use u {\displaystyle u} , v {\displaystyle v} , and w {\displaystyle w} for
2970-501: Is defined as the rate of change of position with respect to time, which may also be referred to as the instantaneous velocity to emphasize the distinction from the average velocity. In some applications the average velocity of an object might be needed, that is to say, the constant velocity that would provide the same resultant displacement as a variable velocity in the same time interval, v ( t ) , over some time period Δ t . Average velocity can be calculated as: The average velocity
3069-435: Is defined as the rate of change of position, it is often common to start with an expression for an object's acceleration . As seen by the three green tangent lines in the figure, an object's instantaneous acceleration at a point in time is the slope of the line tangent to the curve of a v ( t ) graph at that point. In other words, instantaneous acceleration is defined as the derivative of velocity with respect to time:
Wadi - Misplaced Pages Continue
3168-483: Is found by the distance formula as | v | = v x 2 + v y 2 . {\displaystyle |v|={\sqrt {v_{x}^{2}+v_{y}^{2}}}.} In three-dimensional systems where there is an additional z-axis, the corresponding velocity component is defined as v z = d z / d t . {\displaystyle v_{z}=dz/dt.} The three-dimensional velocity vector
3267-635: Is given by the harmonic mean of the speeds v ¯ = n ( 1 v 1 + 1 v 2 + 1 v 3 + ⋯ + 1 v n ) − 1 = n ( ∑ i = 1 n 1 v i ) − 1 . {\displaystyle {\bar {v}}=n\left({1 \over v_{1}}+{1 \over v_{2}}+{1 \over v_{3}}+\dots +{1 \over v_{n}}\right)^{-1}=n\left(\sum _{i=1}^{n}{\frac {1}{v_{i}}}\right)^{-1}.} Although velocity
3366-501: Is measured in the SI ( metric system ) as metres per second (m/s or m⋅s ). For example, "5 metres per second" is a scalar, whereas "5 metres per second east" is a vector. If there is a change in speed, direction or both, then the object is said to be undergoing an acceleration . The average velocity of an object over a period of time is its change in position , Δ s {\displaystyle \Delta s} , divided by
3465-574: Is not present in the spoken varieties, but deletes Classical words that sound obsolete in MSA. In addition, MSA has borrowed or coined many terms for concepts that did not exist in Quranic times, and MSA continues to evolve. Some words have been borrowed from other languages—notice that transliteration mainly indicates spelling and not real pronunciation (e.g., فِلْم film 'film' or ديمقراطية dīmuqrāṭiyyah 'democracy'). The current preference
3564-855: Is official in Mali and recognized as a minority language in Morocco, while the Senegalese government adopted the Latin script to write it. Maltese is official in (predominantly Catholic ) Malta and written with the Latin script . Linguists agree that it is a variety of spoken Arabic, descended from Siculo-Arabic , though it has experienced extensive changes as a result of sustained and intensive contact with Italo-Romance varieties, and more recently also with English. Due to "a mix of social, cultural, historical, political, and indeed linguistic factors", many Maltese people today consider their language Semitic but not
3663-474: Is position and r ^ {\displaystyle {\hat {\boldsymbol {r}}}} is the radial direction. The transverse speed (or magnitude of the transverse velocity) is the magnitude of the cross product of the unit vector in the radial direction and the velocity vector. It is also the dot product of velocity and transverse direction, or the product of the angular speed ω {\displaystyle \omega } and
3762-409: Is the gravitational constant and g is the gravitational acceleration . The escape velocity from Earth's surface is about 11 200 m/s, and is irrespective of the direction of the object. This makes "escape velocity" somewhat of a misnomer, as the more correct term would be "escape speed": any object attaining a velocity of that magnitude, irrespective of atmosphere, will leave the vicinity of
3861-422: Is the speed in combination with the direction of motion of an object . Velocity is a fundamental concept in kinematics , the branch of classical mechanics that describes the motion of bodies. Velocity is a physical vector quantity : both magnitude and direction are needed to define it. The scalar absolute value ( magnitude ) of velocity is called speed , being a coherent derived unit whose quantity
3960-572: Is the third most widespread official language after English and French, one of six official languages of the United Nations , and the liturgical language of Islam . Arabic is widely taught in schools and universities around the world and is used to varying degrees in workplaces, governments and the media. During the Middle Ages , Arabic was a major vehicle of culture and learning, especially in science, mathematics and philosophy. As
4059-769: Is the component of velocity along a circle centered at the origin. v = v T + v R {\displaystyle {\boldsymbol {v}}={\boldsymbol {v}}_{T}+{\boldsymbol {v}}_{R}} where The radial speed (or magnitude of the radial velocity) is the dot product of the velocity vector and the unit vector in the radial direction. v R = v ⋅ r | r | = v ⋅ r ^ {\displaystyle v_{R}={\frac {{\boldsymbol {v}}\cdot {\boldsymbol {r}}}{\left|{\boldsymbol {r}}\right|}}={\boldsymbol {v}}\cdot {\hat {\boldsymbol {r}}}} where r {\displaystyle {\boldsymbol {r}}}
Wadi - Misplaced Pages Continue
4158-418: Is the mass of the object. The kinetic energy of a moving object is dependent on its velocity and is given by the equation E k = 1 2 m v 2 {\displaystyle E_{\text{k}}={\tfrac {1}{2}}mv^{2}} where E k is the kinetic energy. Kinetic energy is a scalar quantity as it depends on the square of the velocity. In fluid dynamics , drag
4257-461: Is the mass times the distance to the origin times the transverse velocity, or equivalently, the mass times the distance squared times the angular speed. The sign convention for angular momentum is the same as that for angular velocity. L = m r v T = m r 2 ω {\displaystyle L=mrv_{T}=mr^{2}\omega } where The expression m r 2 {\displaystyle mr^{2}}
4356-547: Is the minimum speed a ballistic object needs to escape from a massive body such as Earth. It represents the kinetic energy that, when added to the object's gravitational potential energy (which is always negative), is equal to zero. The general formula for the escape velocity of an object at a distance r from the center of a planet with mass M is v e = 2 G M r = 2 g r , {\displaystyle v_{\text{e}}={\sqrt {\frac {2GM}{r}}}={\sqrt {2gr}},} where G
4455-463: Is the rate of rotation about the origin (with positive quantities representing counter-clockwise rotation and negative quantities representing clockwise rotation, in a right-handed coordinate system). The radial and traverse velocities can be derived from the Cartesian velocity and displacement vectors by decomposing the velocity vector into radial and transverse components. The transverse velocity
4554-453: Is the speed of light. Relative velocity is a measurement of velocity between two objects as determined in a single coordinate system. Relative velocity is fundamental in both classical and modern physics, since many systems in physics deal with the relative motion of two or more particles. Consider an object A moving with velocity vector v and an object B with velocity vector w ; these absolute velocities are typically expressed in
4653-590: Is the variety used in most current, printed Arabic publications, spoken by some of the Arabic media across North Africa and the Middle East, and understood by most educated Arabic speakers. "Literary Arabic" and "Standard Arabic" ( فُصْحَى fuṣḥá ) are less strictly defined terms that may refer to Modern Standard Arabic or Classical Arabic. Some of the differences between Classical Arabic (CA) and Modern Standard Arabic (MSA) are as follows: MSA uses much Classical vocabulary (e.g., dhahaba 'to go') that
4752-413: Is to avoid direct borrowings, preferring to either use loan translations (e.g., فرع farʻ 'branch', also used for the branch of a company or organization; جناح janāḥ 'wing', is also used for the wing of an airplane, building, air force, etc.), or to coin new words using forms within existing roots ( استماتة istimātah ' apoptosis ', using the root موت m/w/t 'death' put into
4851-673: Is used in the Americas for similar landforms. The term wādī is very widely found in Arabic toponyms . Some Spanish toponyms are derived from Andalusian Arabic where wādī was used to mean a permanent river, for example: Guadalcanal from wādī al-qanāl ( Arabic : وَادِي الْقَنَال , "river of refreshment stalls"), Guadalajara from wādī al-ḥijārah ( Arabic : وَادِي الْحِجَارَة , "river of stones"), or Guadalquivir , from al-wādī al-kabīr ( Arabic : اَلْوَادِي الْكَبِير , "the great river"). Wadis are located on gently sloping, nearly flat parts of deserts; commonly they begin on
4950-524: Is used to denote concepts that have arisen in the industrial and post-industrial era , especially in modern times. Due to its grounding in Classical Arabic, Modern Standard Arabic is removed over a millennium from everyday speech, which is construed as a multitude of dialects of this language. These dialects and Modern Standard Arabic are described by some scholars as not mutually comprehensible. The former are usually acquired in families, while
5049-436: The x {\displaystyle x} -, y {\displaystyle y} -, and z {\displaystyle z} -axes respectively. In polar coordinates , a two-dimensional velocity is described by a radial velocity , defined as the component of velocity away from or toward the origin, and a transverse velocity , perpendicular to the radial one. Both arise from angular velocity , which
SECTION 50
#17327662157565148-445: The Lisān al-ʻArab ). Modern Standard Arabic (MSA) largely follows the grammatical standards of Classical Arabic and uses much of the same vocabulary. However, it has discarded some grammatical constructions and vocabulary that no longer have any counterpart in the spoken varieties and has adopted certain new constructions and vocabulary from the spoken varieties. Much of the new vocabulary
5247-568: The Xth form , or جامعة jāmiʻah 'university', based on جمع jamaʻa 'to gather, unite'; جمهورية jumhūriyyah 'republic', based on جمهور jumhūr 'multitude'). An earlier tendency was to redefine an older word although this has fallen into disuse (e.g., هاتف hātif 'telephone' < 'invisible caller (in Sufism)'; جريدة jarīdah 'newspaper' < 'palm-leaf stalk'). Colloquial or dialectal Arabic refers to
5346-424: The derivative of the position with respect to time: v = lim Δ t → 0 Δ s Δ t = d s d t . {\displaystyle {\boldsymbol {v}}=\lim _{{\Delta t}\to 0}{\frac {\Delta {\boldsymbol {s}}}{\Delta t}}={\frac {d{\boldsymbol {s}}}{dt}}.} From this derivative equation, in
5445-494: The northern Hejaz . These features are evidence of common descent from a hypothetical ancestor , Proto-Arabic . The following features of Proto-Arabic can be reconstructed with confidence: On the other hand, several Arabic varieties are closer to other Semitic languages and maintain features not found in Classical Arabic, indicating that these varieties cannot have developed from Classical Arabic. Thus, Arabic vernaculars do not descend from Classical Arabic: Classical Arabic
5544-419: The "learned" tradition (Classical Arabic). This variety and both its classicizing and "lay" iterations have been termed Middle Arabic in the past, but they are thought to continue an Old Higazi register. It is clear that the orthography of the Quran was not developed for the standardized form of Classical Arabic; rather, it shows the attempt on the part of writers to record an archaic form of Old Higazi. In
5643-710: The "purest," most eloquent form of Arabic—initiating a process of jamʿu‿l-luɣah ( جمع اللغة 'compiling the language') which took place over the 8th and early 9th centuries. Kitāb al-'Ayn ( c. 8th century ), attributed to Al-Khalil ibn Ahmad al-Farahidi , is considered the first lexicon to include all Arabic roots ; it sought to exhaust all possible root permutations —later called taqālīb ( تقاليب ) — calling those that are actually used mustaʿmal ( مستعمَل ) and those that are not used muhmal ( مُهمَل ). Lisān al-ʿArab (1290) by Ibn Manzur gives 9,273 roots, while Tāj al-ʿArūs (1774) by Murtada az-Zabidi gives 11,978 roots. Velocity Velocity
5742-454: The 11th and 12th centuries in al-Andalus , the zajal and muwashah poetry forms developed in the dialectical Arabic of Cordoba and the Maghreb. The Nahda was a cultural and especially literary renaissance of the 19th century in which writers sought "to fuse Arabic and European forms of expression." According to James L. Gelvin , " Nahda writers attempted to simplify the Arabic language and script so that it might be accessible to
5841-735: The 1990s. Deposition in a wadi is rapid because of the sudden loss of stream velocity and seepage of water into the porous sediment. Wadi deposits are thus usually mixed gravels and sands. These sediments are often altered by eolian processes. Over time, wadi deposits may become "inverted wadis," where former underground water caused vegetation and sediment to fill in the eroded channel, turning previous washes into ridges running through desert regions. Arabic language Arabic (endonym: اَلْعَرَبِيَّةُ , romanized : al-ʿarabiyyah , pronounced [al ʕaraˈbijːa] , or عَرَبِيّ , ʿarabīy , pronounced [ˈʕarabiː] or [ʕaraˈbij] )
5940-571: The 4th to the 6th centuries, the Nabataean script evolved into the Arabic script recognizable from the early Islamic era. There are inscriptions in an undotted, 17-letter Arabic script dating to the 6th century CE, found at four locations in Syria ( Zabad , Jebel Usays , Harran , Umm el-Jimal ). The oldest surviving papyrus in Arabic dates to 643 CE, and it uses dots to produce the modern 28-letter Arabic alphabet. The language of that papyrus and of
6039-834: The 8th century, knowledge of Classical Arabic had become an essential prerequisite for rising into the higher classes throughout the Islamic world, both for Muslims and non-Muslims. For example, Maimonides , the Andalusi Jewish philosopher, authored works in Judeo-Arabic —Arabic written in Hebrew script . Ibn Jinni of Mosul , a pioneer in phonology , wrote prolifically in the 10th century on Arabic morphology and phonology in works such as Kitāb Al-Munṣif , Kitāb Al-Muḥtasab , and Kitāb Al-Khaṣāʾiṣ [ ar ] . Ibn Mada' of Cordoba (1116–1196) realized
SECTION 60
#17327662157566138-412: The Middle East and North Africa have become a badge of sophistication and modernity and ... feigning, or asserting, weakness or lack of facility in Arabic is sometimes paraded as a sign of status, class, and perversely, even education through a mélange of code-switching practises." Arabic has been taught worldwide in many elementary and secondary schools, especially Muslim schools. Universities around
6237-690: The Qur'an is referred to by linguists as "Quranic Arabic", as distinct from its codification soon thereafter into " Classical Arabic ". In late pre-Islamic times, a transdialectal and transcommunal variety of Arabic emerged in the Hejaz , which continued living its parallel life after literary Arabic had been institutionally standardized in the 2nd and 3rd century of the Hijra , most strongly in Judeo-Christian texts, keeping alive ancient features eliminated from
6336-576: The Romance languages. Also, while it is comprehensible to people from the Maghreb , a linguistically innovative variety such as Moroccan Arabic is essentially incomprehensible to Arabs from the Mashriq , much as French is incomprehensible to Spanish or Italian speakers but relatively easily learned by them. This suggests that the spoken varieties may linguistically be considered separate languages. With
6435-425: The action and prevalence of water. Wadis, as drainage courses, are formed by water, but are distinguished from river valleys or gullies in that surface water is intermittent or ephemeral. Wadis are generally dry year round, except after a rain. The desert environment is characterized by sudden but infrequent heavy rainfall, often resulting in flash floods . Crossing wadis at certain times of the year can be dangerous as
6534-1574: The average velocity as the slope of the secant line between two points with t coordinates equal to the boundaries of the time period for the average velocity. If t 1 = t 2 = t 3 = ... = t , then average speed is given by the arithmetic mean of the speeds v ¯ = v 1 + v 2 + v 3 + ⋯ + v n n = 1 n ∑ i = 1 n v i {\displaystyle {\bar {v}}={v_{1}+v_{2}+v_{3}+\dots +v_{n} \over n}={\frac {1}{n}}\sum _{i=1}^{n}{v_{i}}} v ¯ = s 1 + s 2 + s 3 + ⋯ + s n t 1 + t 2 + t 3 + ⋯ + t n = s 1 + s 2 + s 3 + ⋯ + s n s 1 v 1 + s 2 v 2 + s 3 v 3 + ⋯ + s n v n {\displaystyle {\bar {v}}={s_{1}+s_{2}+s_{3}+\dots +s_{n} \over t_{1}+t_{2}+t_{3}+\dots +t_{n}}={{s_{1}+s_{2}+s_{3}+\dots +s_{n}} \over {{s_{1} \over v_{1}}+{s_{2} \over v_{2}}+{s_{3} \over v_{3}}+\dots +{s_{n} \over v_{n}}}}} If s 1 = s 2 = s 3 = ... = s , then average speed
6633-456: The base body as long as it does not intersect with something in its path. In special relativity , the dimensionless Lorentz factor appears frequently, and is given by γ = 1 1 − v 2 c 2 {\displaystyle \gamma ={\frac {1}{\sqrt {1-{\frac {v^{2}}{c^{2}}}}}}} where γ is the Lorentz factor and c
6732-402: The concept of an instantaneous velocity might at first seem counter-intuitive, it may be thought of as the velocity that the object would continue to travel at if it stopped accelerating at that moment. While the terms speed and velocity are often colloquially used interchangeably to connote how fast an object is moving, in scientific terms they are different. Speed, the scalar magnitude of
6831-574: The conversion of Semitic mimation to nunation in the singular. It is best reassessed as a separate language on the Central Semitic dialect continuum. It was also thought that Old Arabic coexisted alongside—and then gradually displaced— epigraphic Ancient North Arabian (ANA), which was theorized to have been the regional tongue for many centuries. ANA, despite its name, was considered a very distinct language, and mutually unintelligible, from "Arabic". Scholars named its variant dialects after
6930-504: The distal portions of alluvial fans and extend to inland sabkhas or dry lakes . In basin and range topography , wadis trend along basin axes at the terminus of fans. Permanent channels do not exist, due to lack of continual water flow. They have braided stream patterns because of the deficiency of water and the abundance of sediments . Water percolates down into the stream bed, causing an abrupt loss of energy and resulting in vast deposition. Wadis may develop dams of sediment that change
7029-458: The duration of the period, Δ t {\displaystyle \Delta t} , given mathematically as v ¯ = Δ s Δ t . {\displaystyle {\bar {v}}={\frac {\Delta s}{\Delta t}}.} The instantaneous velocity of an object is the limit average velocity as the time interval approaches zero. At any particular time t , it can be calculated as
7128-587: The emergence of Central Semitic languages, particularly in grammar. Innovations of the Central Semitic languages—all maintained in Arabic—include: There are several features which Classical Arabic, the modern Arabic varieties, as well as the Safaitic and Hismaic inscriptions share which are unattested in any other Central Semitic language variety, including the Dadanitic and Taymanitic languages of
7227-728: The eve of the conquests: Northern and Central (Al-Jallad 2009). The modern dialects emerged from a new contact situation produced following the conquests. Instead of the emergence of a single or multiple koines, the dialects contain several sedimentary layers of borrowed and areal features, which they absorbed at different points in their linguistic histories. According to Veersteegh and Bickerton, colloquial Arabic dialects arose from pidginized Arabic formed from contact between Arabs and conquered peoples. Pidginization and subsequent creolization among Arabs and arabized peoples could explain relative morphological and phonological simplicity of vernacular Arabic compared to Classical and MSA. In around
7326-607: The fact that they participate in the innovations common to all forms of Arabic. The earliest attestation of continuous Arabic text in an ancestor of the modern Arabic script are three lines of poetry by a man named Garm(')allāhe found in En Avdat, Israel , and dated to around 125 CE. This is followed by the Namara inscription , an epitaph of the Lakhmid king Imru' al-Qays bar 'Amro, dating to 328 CE, found at Namaraa, Syria. From
7425-510: The fourth most useful language for business, after English, Mandarin Chinese , and French. Arabic is written with the Arabic alphabet , an abjad script that is written from right to left . Arabic is usually classified as a Central Semitic language . Linguists still differ as to the best classification of Semitic language sub-groups. The Semitic languages changed between Proto-Semitic and
7524-597: The inclusion of new words into their published standard dictionaries. They also publish old and historical Arabic manuscripts. In 1997, a bureau of Arabization standardization was added to the Educational, Cultural, and Scientific Organization of the Arab League . These academies and organizations have worked toward the Arabization of the sciences, creating terms in Arabic to describe new concepts, toward
7623-540: The inertial frame chosen is that in which the latter of the two mentioned objects is in rest. In Newtonian mechanics, the relative velocity is independent of the chosen inertial reference frame. This is not the case anymore with special relativity in which velocities depend on the choice of reference frame. In the one-dimensional case, the velocities are scalars and the equation is either: v rel = v − ( − w ) , {\displaystyle v_{\text{rel}}=v-(-w),} if
7722-613: The language. Software and books with tapes are an important part of Arabic learning, as many of Arabic learners may live in places where there are no academic or Arabic language school classes available. Radio series of Arabic language classes are also provided from some radio stations. A number of websites on the Internet provide online classes for all levels as a means of distance education; most teach Modern Standard Arabic, but some teach regional varieties from numerous countries. The tradition of Arabic lexicography extended for about
7821-604: The late 6th century AD, a relatively uniform intertribal "poetic koine" distinct from the spoken vernaculars developed based on the Bedouin dialects of Najd , probably in connection with the court of al-Ḥīra . During the first Islamic century, the majority of Arabic poets and Arabic-writing persons spoke Arabic as their mother tongue. Their texts, although mainly preserved in far later manuscripts, contain traces of non-standardized Classical Arabic elements in morphology and syntax. Abu al-Aswad al-Du'ali ( c. 603 –689)
7920-420: The latter is taught in formal education settings. However, there have been studies reporting some degree of comprehension of stories told in the standard variety among preschool-aged children. The relation between Modern Standard Arabic and these dialects is sometimes compared to that of Classical Latin and Vulgar Latin vernaculars (which became Romance languages ) in medieval and early modern Europe. MSA
8019-883: The many national or regional varieties which constitute the everyday spoken language. Colloquial Arabic has many regional variants; geographically distant varieties usually differ enough to be mutually unintelligible , and some linguists consider them distinct languages. However, research indicates a high degree of mutual intelligibility between closely related Arabic variants for native speakers listening to words, sentences, and texts; and between more distantly related dialects in interactional situations. The varieties are typically unwritten. They are often used in informal spoken media, such as soap operas and talk shows , as well as occasionally in certain forms of written media such as poetry and printed advertising. Hassaniya Arabic , Maltese , and Cypriot Arabic are only varieties of modern Arabic to have acquired official recognition. Hassaniya
8118-782: The need for a lexical injection in Arabic, to suit concepts of the industrial and post-industrial age (such as sayyārah سَيَّارَة 'automobile' or bākhirah باخِرة 'steamship'). In response, a number of Arabic academies modeled after the Académie française were established with the aim of developing standardized additions to the Arabic lexicon to suit these transformations, first in Damascus (1919), then in Cairo (1932), Baghdad (1948), Rabat (1960), Amman (1977), Khartum [ ar ] (1993), and Tunis (1993). They review language development, monitor new words and approve
8217-424: The one whose sound is heard but whose person remains unseen. Now the term al-hatif is used for a telephone. Therefore, the process of tawleed can express the needs of modern civilization in a manner that would appear to be originally Arabic. In the case of Arabic, educated Arabs of any nationality can be assumed to speak both their school-taught Standard Arabic as well as their native dialects, which depending on
8316-477: The one-dimensional case it can be seen that the area under a velocity vs. time ( v vs. t graph) is the displacement, s . In calculus terms, the integral of the velocity function v ( t ) is the displacement function s ( t ) . In the figure, this corresponds to the yellow area under the curve. s = ∫ v d t . {\displaystyle {\boldsymbol {s}}=\int {\boldsymbol {v}}\ dt.} Although
8415-549: The overhaul of Arabic grammar first proposed by Al-Jahiz 200 years prior. The Maghrebi lexicographer Ibn Manzur compiled Lisān al-ʿArab ( لسان العرب , "Tongue of Arabs"), a major reference dictionary of Arabic, in 1290. Charles Ferguson 's koine theory claims that the modern Arabic dialects collectively descend from a single military koine that sprang up during the Islamic conquests; this view has been challenged in recent times. Ahmad al-Jallad proposes that there were at least two considerably distinct types of Arabic on
8514-754: The radius (the magnitude of the position). v T = | r × v | | r | = v ⋅ t ^ = ω | r | {\displaystyle v_{T}={\frac {|{\boldsymbol {r}}\times {\boldsymbol {v}}|}{|{\boldsymbol {r}}|}}={\boldsymbol {v}}\cdot {\hat {\boldsymbol {t}}}=\omega |{\boldsymbol {r}}|} such that ω = | r × v | | r | 2 . {\displaystyle \omega ={\frac {|{\boldsymbol {r}}\times {\boldsymbol {v}}|}{|{\boldsymbol {r}}|^{2}}}.} Angular momentum in scalar form
8613-410: The region may be mutually unintelligible. Some of these dialects can be considered to constitute separate languages which may have "sub-dialects" of their own. When educated Arabs of different dialects engage in conversation (for example, a Moroccan speaking with a Lebanese), many speakers code-switch back and forth between the dialectal and standard varieties of the language, sometimes even within
8712-710: The same inertial reference frame . Then, the velocity of object A relative to object B is defined as the difference of the two velocity vectors: v A relative to B = v − w {\displaystyle {\boldsymbol {v}}_{A{\text{ relative to }}B}={\boldsymbol {v}}-{\boldsymbol {w}}} Similarly, the relative velocity of object B moving with velocity w , relative to object A moving with velocity v is: v B relative to A = w − v {\displaystyle {\boldsymbol {v}}_{B{\text{ relative to }}A}={\boldsymbol {w}}-{\boldsymbol {v}}} Usually,
8811-458: The same sentence. The issue of whether Arabic is one language or many languages is politically charged, in the same way it is for the varieties of Chinese , Hindi and Urdu , Serbian and Croatian , Scots and English, etc. In contrast to speakers of Hindi and Urdu who claim they cannot understand each other even when they can, speakers of the varieties of Arabic will claim they can all understand each other even when they cannot. While there
8910-458: The sole example of Medieval linguist Abu Hayyan al-Gharnati – who, while a scholar of the Arabic language, was not ethnically Arab – Medieval scholars of the Arabic language made no efforts at studying comparative linguistics, considering all other languages inferior. In modern times, the educated upper classes in the Arab world have taken a nearly opposite view. Yasir Suleiman wrote in 2011 that "studying and knowing English or French in most of
9009-432: The special case of constant acceleration, velocity can be studied using the suvat equations . By considering a as being equal to some arbitrary constant vector, this shows v = u + a t {\displaystyle {\boldsymbol {v}}={\boldsymbol {u}}+{\boldsymbol {a}}t} with v as the velocity at time t and u as the velocity at time t = 0 . By combining this equation with
9108-563: The standardization of these new terms throughout the Arabic-speaking world, and toward the development of Arabic as a world language . This gave rise to what Western scholars call Modern Standard Arabic. From the 1950s, Arabization became a postcolonial nationalist policy in countries such as Tunisia, Algeria, Morocco, and Sudan. Arabic usually refers to Standard Arabic, which Western linguists divide into Classical Arabic and Modern Standard Arabic. It could also refer to any of
9207-485: The stream patterns in the next flash flood . Wind also causes sediment deposition. When wadi sediments are underwater or moist, wind sediments are deposited over them. Thus, wadi sediments contain both wind and water sediments. Wadi sediments may contain a range of material, from gravel to mud, and the sedimentary structures vary widely. Thus, wadi sediments are the most diverse of all desert environments. Flash floods result from severe energy conditions and can result in
9306-415: The suvat equation x = u t + a t /2 , it is possible to relate the displacement and the average velocity by x = ( u + v ) 2 t = v ¯ t . {\displaystyle {\boldsymbol {x}}={\frac {({\boldsymbol {u}}+{\boldsymbol {v}})}{2}}t={\boldsymbol {\bar {v}}}t.} It is also possible to derive an expression for
9405-501: The towns where the inscriptions were discovered (Dadanitic, Taymanitic, Hismaic, Safaitic). However, most arguments for a single ANA language or language family were based on the shape of the definite article, a prefixed h-. It has been argued that the h- is an archaism and not a shared innovation, and thus unsuitable for language classification, rendering the hypothesis of an ANA language family untenable. Safaitic and Hismaic, previously considered ANA, should be considered Old Arabic due to
9504-401: The two objects are moving in opposite directions, or: v rel = v − ( + w ) , {\displaystyle v_{\text{rel}}=v-(+w),} if the two objects are moving in the same direction. In multi-dimensional Cartesian coordinate systems , velocity is broken up into components that correspond with each dimensional axis of the coordinate system. In
9603-555: The value of t and the transformation rules for position create a situation in which all non-accelerating observers would describe the acceleration of an object with the same values. Neither is true for special relativity. In other words, only relative velocity can be calculated. In classical mechanics, Newton's second law defines momentum , p, as a vector that is the product of an object's mass and velocity, given mathematically as p = m v {\displaystyle {\boldsymbol {p}}=m{\boldsymbol {v}}} where m
9702-654: The velocity independent of time, known as the Torricelli equation , as follows: v 2 = v ⋅ v = ( u + a t ) ⋅ ( u + a t ) = u 2 + 2 t ( a ⋅ u ) + a 2 t 2 {\displaystyle v^{2}={\boldsymbol {v}}\cdot {\boldsymbol {v}}=({\boldsymbol {u}}+{\boldsymbol {a}}t)\cdot ({\boldsymbol {u}}+{\boldsymbol {a}}t)=u^{2}+2t({\boldsymbol {a}}\cdot {\boldsymbol {u}})+a^{2}t^{2}} ( 2
9801-451: The world have classes that teach Arabic as part of their foreign languages , Middle Eastern studies , and religious studies courses. Arabic language schools exist to assist students to learn Arabic outside the academic world. There are many Arabic language schools in the Arab world and other Muslim countries. Because the Quran is written in Arabic and all Islamic terms are in Arabic, millions of Muslims (both Arab and non-Arab) study
#755244