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40-445: Sounds are traveling vibrations in the form of pressure waves in an elastic medium. Objects move at supersonic speed when the objects move faster than the speed at which sound propagates through the medium. In gases, sound travels longitudinally at different speeds, mostly depending on the molecular mass and temperature of the gas, and pressure has little effect. Since air temperature and composition varies significantly with altitude,

80-442: A conversion factor, describing the shape of a particular molecule. This allows the apparent molecular mass to be described from a range of techniques sensitive to hydrodynamic effects, including DLS , SEC (also known as GPC when the eluent is an organic solvent), viscometry , and diffusion ordered nuclear magnetic resonance spectroscopy (DOSY). The apparent hydrodynamic size can then be used to approximate molecular mass using

120-535: A maximum of Mach   0.95 with all supersonic speeds beyond subsonic cruise attained with afterburning. All the Fairey Delta 2 initial supersonic test flying to Mach   1.1 was done without afterburning. Selecting the afterburner, which initially only had a maximum selection with no intermediate positions, would have caused an uncontrollable rapid acceleration to potentially hazardous speeds; i.e., too far beyond previously established flutter-free speeds. Only

160-529: A series of macromolecule-specific standards. As this requires calibration, it's frequently described as a "relative" molecular mass determination method. It is also possible to determine absolute molecular mass directly from light scattering, traditionally using the Zimm method . This can be accomplished either via classical static light scattering or via multi-angle light scattering detectors. Molecular masses determined by this method do not require calibration, hence

200-419: A wide range of molecular masses (40 kDa – 5 MDa). To a first approximation, the basis for determination of molecular mass according to Mark–Houwink relations is the fact that the intrinsic viscosity of solutions (or suspensions ) of macromolecules depends on volumetric proportion of the dispersed particles in a particular solvent. Specifically, the hydrodynamic size as related to molecular mass depends on

240-409: Is CH 4 , are calculated respectively as follows: The uncertainty in molecular mass reflects variance (error) in measurement not the natural variance in isotopic abundances across the globe. In high-resolution mass spectrometry the mass isotopomers C H 4 and C H 4 are observed as distinct molecules, with molecular masses of approximately 16.031 Da and 17.035 Da, respectively. The intensity of

280-511: Is actually just a sonic boom . The first human-made supersonic boom was likely caused by a piece of common cloth, leading to the whip's eventual development. It's the wave motion travelling through the bullwhip that makes it capable of achieving supersonic speeds. Most modern firearm bullets are supersonic, with rifle projectiles often travelling at speeds approaching and in some cases well exceeding Mach 3 . Most spacecraft are supersonic at least during portions of their reentry, though

320-424: Is defined in terms of the mass of the isotope C (carbon-12). However, the name unified atomic mass unit (u) is still used in common practice. Relative atomic and molecular masses as defined are dimensionless . Molar masses when expressed in g / mol have almost identical numerical values as relative atomic and molecular masses. For example, the molar mass and molecular mass of methane , whose molecular formula

360-444: Is more complex. The main key to having low supersonic drag is to properly shape the overall aircraft to be long and thin, and close to a "perfect" shape, the von Karman ogive or Sears-Haack body . This has led to almost every supersonic cruising aircraft looking very similar to every other, with a very long and slender fuselage and large delta wings, cf. SR-71 , Concorde , etc. Although not ideal for passenger aircraft, this shaping

400-482: Is not needed. The molecular mass is more commonly used when referring to the mass of a single or specific well-defined molecule and less commonly than molecular weight when referring to a weighted average of a sample. Prior to the 2019 revision of the SI quantities expressed in daltons (Da) were by definition numerically equivalent to molar mass expressed in the units g/mol and were thus strictly numerically interchangeable. After

440-400: Is quite adaptable for bomber use. Molecular mass The molecular mass ( m ) is the mass of a given molecule . Units of daltons (Da) are often used. Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. The derived quantity relative molecular mass is the unitless ratio of the mass of a molecule to

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480-478: Is underway to add supercruise ability to the Sukhoi Su-57 . This has yet to bear fruit, but the stop-gap 117S engine, produced by this program, may achieve the supercruise goal already. While testing a Su-35BM fighter equipped with these engines, it managed to accelerate past Mach 1 without using the afterburner, suggesting that it had supercruise capability. It has yet to be seen whether this will be possible with

520-570: The Advanced Tactical Fighter program, which resulted in the F-22 Raptor . The F-22 Raptor's supercruise capabilities are touted as a major performance advantage over other fighters, with supercruise being demonstrated exceeding Mach   1.5. Supercruise capability provides advantages for stealth aircraft because an afterburner plume reflects radar signals and creates a significant infrared signature . Virtually all fighters prior to

560-544: The Black Rock Desert on 15 October 1997. The Bloodhound LSR project planned an attempt on the record in 2020 at Hakskeenpan in South Africa with a combination jet and hybrid rocket propelled car. The aim was to break the existing record, then make further attempts during which (the members of) the team hoped to reach speeds of up to 1,600 km/h (1,000 mph). The effort was originally run by Richard Noble who

600-474: The SR-71 Blackbird are designed to cruise at supersonic speed with afterburners enabled. Some fighter jets are capable of supercruise but only at high altitudes and in a clean configuration , so the term may imply "a significant increase in effective combat speed with a full weapons load over existing types". One of the pre-eminent military examples of supercruise is the F-22 Raptor , for which supercruise

640-629: The Tupolev Tu-144 . Both of these passenger aircraft and some modern fighters are also capable of supercruise , a condition of sustained supersonic flight without the use of an afterburner . Due to its ability to supercruise for several hours and the relatively high frequency of flight over several decades, Concorde spent more time flying supersonically than all other aircraft combined by a considerable margin. Since Concorde's final retirement flight on November 26, 2003, there are no supersonic passenger aircraft left in service. Some large bombers , such as

680-555: The Tupolev Tu-160 and Rockwell B-1 Lancer are also supersonic-capable. The aerodynamics of supersonic aircraft is simpler than subsonic aerodynamics because the airsheets at different points along the plane often cannot affect each other. Supersonic jets and rocket vehicles require several times greater thrust to push through the extra aerodynamic drag experienced within the transonic region (around Mach 0.85–1.2). At these speeds aerospace engineers can gently guide air around

720-430: The atomic mass constant (which is equal to one dalton). The molecular mass and relative molecular mass are distinct from but related to the molar mass . The molar mass is defined as the mass of a given substance divided by the amount of the substance , and is expressed in grams per mol (g/mol). That makes the molar mass an average of many particles or molecules (potentially containing different isotopes ), and

760-650: The atomic masses of each nuclide present in the molecule, while molar masses and relative molecular masses (molecular weights) are calculated from the standard atomic weights of each element . The standard atomic weight takes into account the isotopic distribution of the element in a given sample (usually assumed to be "normal"). For example, water has a molar mass of 18.0153(3) g/mol, but individual water molecules have molecular masses which range between 18.010 564 6863(15) Da ( H 2 O) and 22.027 7364(9) Da ( H 2 O). Atomic and molecular masses are usually reported in daltons , which

800-513: The fuselage of the aircraft without producing new shock waves , but any change in cross area farther down the vehicle leads to shock waves along the body. Designers use the Supersonic area rule and the Whitcomb area rule to minimize sudden changes in size. However, in practical applications, a supersonic aircraft must operate stably in both subsonic and supersonic profiles, hence aerodynamic design

840-503: The supersonic transports (SST), Concorde, and the second version of the Tu-144 (the Tu-144D ) spent most of their time cruising at their design speeds without needing afterburning. Afterburning was added to Concorde for take-off to cope with weight increases that came after the initial design. It was also used to accelerate through the high-drag transonic speed range, not because the extra thrust

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880-601: The 2019 revision, this relationship is only nearly equivalent, although the difference is negligible for all practical purposes. The molecular mass of small to medium size molecules, measured by mass spectrometry, can be used to determine the composition of elements in the molecule. The molecular masses of macromolecules, such as proteins, can also be determined by mass spectrometry; however, methods based on viscosity and light-scattering are also used to determine molecular mass when crystallographic or mass spectrometric data are not available. Molecular masses are calculated from

920-446: The F-22 cruise at Mach   0.8–0.9 while carrying a normal weapons load. There are a few engines in production that are designed to facilitate tactically significant supercruise: Independently, Russia is working on izdeliye 30 (after AL-31F and AL-41F derivatives modifications, like izdeliye 117S turbofan) and RD-33MKRU Morskaja Osa; an all-new AL-41 engine with a complete redesign

960-445: The beginning of the 20th century, the term "supersonic" was used as an adjective to describe sound whose frequency is above the range of normal human hearing. The modern term for this meaning is " ultrasonic ", but the older meaning sometimes still lives on, as in the word superheterodyne The tip of a bullwhip is generally seen as the first object designed to reach the speed of sound. This action results in its telltale "crack", which

1000-409: The choice of isotopes is defined and thus is a single specific molecular mass out of the (perhaps many) possibilities. The masses used to compute the monoisotopic molecular mass are found in a table of isotopic masses and are not found in a typical periodic table. The average molecular mass is often used for larger molecules, since molecules with many atoms are often unlikely to be composed exclusively of

1040-414: The effects on the spacecraft are reduced by low air densities. During ascent, launch vehicles generally avoid going supersonic below 30 km (~98,400 feet) to reduce air drag. Note that the speed of sound decreases somewhat with altitude, due to lower temperatures found there (typically up to 25 km). At even higher altitudes the temperature starts increasing, with the corresponding increase in

1080-420: The mass-spectrometry peaks is proportional to the isotopic abundances in the molecular species. C H H 3 can also be observed with molecular mass of 17 Da. In mass spectrometry, the molecular mass of a small molecule is usually reported as the monoisotopic mass : that is, the mass of the molecule containing only the most common isotope of each element. This also differs subtly from the molecular mass in that

1120-664: The molecular mass of proteins, lipids, sugars and nucleic acids at the single-molecule level. The technique is based on interferometric scattered light microscopy. Contrast from scattered light by a single binding event at the interface between the protein solution and glass slide is detected and is linearly proportional to the mass of the molecule. This technique can also be used to measure sample homogeneity, to detect protein oligomerisation states, and to identify complex macromolecular assemblies ( ribosomes , GroEL , AAV ) and protein interactions such as protein-protein interactions. Mass photometry can accurately measure molecular mass over

1160-408: The molecular mass the mass of one specific particle or molecule. The molar mass is usually the more appropriate quantity when dealing with macroscopic (weigh-able) quantities of a substance. The definition of molecular weight is most authoritatively synonymous with relative molecular mass; however, in common practice, use of this terminology is highly variable. When the molecular weight is given with

1200-449: The most abundant isotope of each element. A theoretical average molecular mass can be calculated using the standard atomic weights found in a typical periodic table. The average molecular mass of a very small sample, however, might differ substantially from this since a single sample average is not the same as the average of many geographically distributed samples. Mass photometry (MP) is a rapid, in-solution, label-free method of obtaining

1240-503: The speed of sound without using afterburning. On 3   August 1954, a Gerfaut research aircraft powered by an SNECMA Atar 101 D2A engine exceeded Mach   1 in level flight without using afterburning. The first production aircraft to exceed Mach   1 in level flight without afterburning was the Lockheed F-104 Starfighter after its J65 engine was replaced with a J79 . The maximum speed without afterburning

Supersonic speed - Misplaced Pages Continue

1280-549: The speed of sound, and Mach numbers for a steadily moving object may change. In water at room temperature supersonic speed means any speed greater than 1,440 m/s (4,724 ft/s). In solids, sound waves can be polarized longitudinally or transversely and have higher velocities. Supersonic fracture is crack formation faster than the speed of sound in a brittle material. The word supersonic comes from two Latin derived words ; 1) super : above and 2) sonus : sound, which together mean above sound, or faster than sound. At

1320-485: The speed of sound. When an inflated balloon is burst, the torn pieces of latex contract at supersonic speed, which contributes to the sharp and loud popping noise. To date, only one land vehicle has officially travelled at supersonic speed, the ThrustSSC . The vehicle, driven by Andy Green , holds the world land speed record, having achieved an average speed on its bi-directional run of 1,228 km/h (763 mph) in

1360-489: The term "absolute". The only external measurement required is refractive index increment , which describes the change in refractive index with concentration. Supercruise Supercruise is sustained supersonic flight of a supersonic aircraft without using afterburner . Many supersonic military aircraft are not capable of supercruise and can maintain Mach 1+ flight only in short bursts with afterburners. Aircraft such as

1400-458: The unit Da, it is frequently as a weighted average similar to the molar mass but with different units. In molecular biology, the mass of macromolecules is referred to as their molecular weight and is expressed in kDa, although the numerical value is often approximate and representative of an average. The terms "molecular mass", "molecular weight", and "molar mass" may be used interchangeably in less formal contexts where unit- and quantity-correctness

1440-473: Was Mach   1.05. The P.1 prototype of the English Electric Lightning , powered by non-afterburning Armstrong Siddeley Sapphire engines, exceeded Mach   1 on 11   August 1954. A week previously, on 4   August, the P.1, WG760 flown by Roland Beamont on its maiden flight , had unknowingly exceeded Mach   1 in a climb. During development testing at English Electric it

1480-587: Was defined as "the ability to cruise at speeds of one and a half times the speed of sound or greater without the use of afterburner for extended periods in combat configuration." One of the best-known examples of an aircraft capable of supercruise, and the only notable non-military example, was the Concorde . Due to its long service as a commercial airliner, Concorde holds the record for the most time spent supersonic; more than all other western aircraft combined. A few early supersonic aircraft attained speeds just beyond

1520-568: Was established that the Lightning had a stabilized speed capability in level flight, without afterburning, of about Mach   1.2 and for the T.4 (2-seat trainer) 1.08. Flying just above the speed of sound without using afterburning, although done by the contractor as part of some flight trials does not appear to have been relevant to the operational capability of the aircraft. Service trials established intercept profiles for subsonic and supersonic targets at different altitudes with subsonic cruising at

1560-406: Was required, but because it was available and improved the operating economics. The redesigned Tu-144D used engines with no afterburners which, together with other improvements, increased the full payload range from 3,080 to 5,330 km (1,910 to 3,310 mi) (Concorde's operational range was 6,470 km or 4,020 mi). The United States Air Force set supercruise as a core requirement for

1600-560: Was the leader of the ThrustSSC project, however following funding issues in 2018, the team was bought by Ian Warhurst and renamed Bloodhound LSR. Later the project was indefinitely delayed due to the COVID-19 pandemic and the vehicle was put up for sale. Most modern fighter aircraft are supersonic aircraft. No modern-day passenger aircraft are capable of supersonic speed, but there have been supersonic passenger aircraft , namely Concorde and

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