Ghosts z

17BBC7EA350
17BBC99D8B0

https://file.io/9e6QoCDtmNPa

computer-connection-scheme-vector-3105602.jpg shared with file.io - super simple file sharing

Encyclopedia Britannica
Search Britannica
Search Britannica...
HomeGames & QuizzesHistory & SocietyScience & TechBiographiesAnimals & NatureGeography & TravelArts & CultureMoneyVideos
ballistics
Table of Contents
Introduction
References & Edit History
Related Topics
Images
trajectory of a bullet
For Students

ballistics summary
Discover
An ancient egyptian hieroglyphic painted carving showing the falcon headed god Horus seated on a throne and holding a golden fly whisk. Before him are the Pharoah Seti and the goddess Isis. Interior wall of the temple to Osiris at Abydos, Egypt.
11 Egyptian Gods and Goddesses
Saint Lucia Day. Young girl wears Lucia crown (tinsel halo) with candles. Holds Saint Lucia Day currant laced saffron buns (lussekatter or Lucia's cats). Observed December 13 honor virgin martyr Santa Lucia (St. Lucy). Luciadagen, Christmas, Sweden
7 Winter Solstice Celebrations From Around the World
Orange basketball on black background and with low key lighting. Homepage 2010, arts and entertainment, history and society
The 10 Greatest Basketball Players of All Time
The Colosseum, Rome, Italy. Giant amphitheatre built in Rome under the Flavian emperors. (ancient architecture; architectural ruins)
New Seven Wonders of the World
Nativity Scene, Adoration of the Magi, Church of the Birth of the Virgin Mary, Montenegro
Why Is Christmas in December?
Groups of depositors in front of the closed American Union Bank, New York City. April 26, 1932. Great Depression run on bank crowd
Causes of the Great Depression
Christmas tree, holiday, pine
How Did the Tradition of Christmas Trees Start?
Home
Science
Physics
Science & Tech
ballistics
projectiles

Written and fact-checked by
Last Updated: Article History
trajectory of a bullet
trajectory of a bullet
See all media
Category: Science & Tech
Key People: Sir Andrew Noble, 1st Baronet Niccolò Fontana Tartaglia Gregory Breit Gilbert Ames Bliss
Related Topics: wound ballistics terminal ballistics projectile motion gunnery intermediate ballistics
Ballistics, science of the propulsion, flight, and impact of projectiles. It is divided into several disciplines. Internal and external ballistics, respectively, deal with the propulsion and the flight of projectiles. The transition between these two regimes is called intermediate ballistics. Terminal ballistics concerns the impact of projectiles; a separate category encompasses the wounding of personnel.

The gun and the rocket motor are types of heat engine, partially converting the chemical energy of a propellant into the kinetic energy of a projectile. Propellants are unlike conventional fuels in that their combustion does not require atmospheric oxygen. Within a restricted volume, the production of hot gases by a burning propellant causes an increase in pressure. The pressure propels the projectile and increases the burning rate. The hot gases tend to erode the gun bore or rocket throat.

Red Army
More From Britannica
military technology: Refinements in ballistics
When the charge of propellant in a gun chamber is ignited, the combustion gases are restrained by the shot, so the pressure rises. The shot starts to move when the pressure on it overcomes its resistance to motion. The pressure continues to rise for a time and then falls, while the shot is accelerated to a high velocity. The rapidly burning propellant is soon exhausted, and, in time, the shot is ejected from the muzzle: muzzle velocities up to 15 kilometres (9 miles) per second have been achieved. Recoilless guns vent gas through the rear of the chamber to counteract recoil forces.

A precursor blast, which precedes the exit of the shot, is followed by the main blast as the compressed gases behind the shot are released. The shot is briefly overtaken by the rapid gas outflow and so may suffer severe yawing. The blast shock wave, traveling outward at a speed greater than that of sound, is heard as gunfire. Heat generated near the muzzle causes flash, which in large guns is accompanied by flames. Devices can be affixed to the muzzle to suppress blast and flash by dispersing shock waves, and they can reduce recoil by deflecting the outflow.

A trajectory is the path of a shot, subject to the forces of gravity, drag, and lift. Under the sole influence of gravity, a trajectory is parabolic. Drag retards motion along the trajectory. Below the speed of sound, the drag is roughly proportional to the square of the velocity; streamlining of the shot tail is effective only at these velocities. At greater velocities, a conical shock wave emanates from the nose of the shot. The drag, which is largely dependent on the nose shape, is least for finely pointed shots. Drag can be reduced by venting gases from a burner in the tail.

Tail fins can be used to stabilize projectiles. Spin stabilization, provided by rifling, causes gyroscopic wobbling in response to aerodynamic tumbling forces. Insufficient spin permits tumbling, and too much prevents dipping of the shot nose as it traverses the trajectory. Drift of the shot arises from lift, due to yawing, meteorological conditions, and rotation of the Earth.

Get a Britannica Premium subscription and gain access to exclusive content.
Subscribe Now
Rockets are propelled by reaction to the momentum of the gas efflux. The motor is designed so that the pressures generated are nearly constant during burning. Fin-stabilized rockets are sensitive to crosswinds, as resulting yaw causes thrust misalignment. Two or more motor nozzles canted from the line of flight can provide spin stabilization.

Targets are generally solid and are termed thick or thin according to whether or not the impact of the shot is influenced by underlying material. Pe*******on occurs when the stress intensities of impact exceed the yield stress of the target; it causes ductile and brittle failure in thin targets and hydrodynamic flow of material in thick targets. The shot may be subject to similar failure during impact. Pe*******on completely through the target is called perforation. Enhanced armour penetrators either detonate a squashed explosive against the target or explosively focus a jet of metal onto its surface.

Wound ballistics is mainly concerned with the mechanisms and medical implications of trauma caused by bullets and explosively driven fragments. Upon pe*******on, the momentum given to the surrounding tissues generates a large temporary cavity. The extent of local injury is related to the size of this transient cavity. Evidence suggests that physical injury is proportional to the projectile’s velocity cubed, its mass, and its cross-sectional area. The wounding potential of a bullet is thus increased by tumbling or mushrooming upon impact. Further injury is often caused by fast-moving fragments of impacted bone. Studies of body armour seek to prevent projectile pe*******on and minimize injury.

This article was most recently revised and updated by John P. Rafferty.
Gilbert Ames Bliss
Table of Contents
Introduction
References & Edit History
Quick Facts & Related Topics
Quizzes
Equations written on blackboard
Numbers and Mathematics
Read Next
bunch of numbers
Unusual Counting Systems
number zero, 0 balloon
Is Zero an Even or an Odd Number?
Discover
The Battle of New Orleans, by E. Percy Moran, c. 1910. Andrew Jackson, War of 1812.
26 Decade-Defining Events in U.S. History
Groups of depositors in front of the closed American Union Bank, New York City. April 26, 1932. Great Depression run on bank crowd
Causes of the Great Depression
Saint Lucia Day. Young girl wears Lucia crown (tinsel halo) with candles. Holds Saint Lucia Day currant laced saffron buns (lussekatter or Lucia's cats). Observed December 13 honor virgin martyr Santa Lucia (St. Lucy). Luciadagen, Christmas, Sweden
7 Winter Solstice Celebrations From Around the World
Queen Elizabeth II addresses at opening of Parliament. (Date unknown on photo, but may be 1958, the first time the opening of Parliament was filmed.)
All 119 References in “We Didn’t Start the Fire,” Explained
Alpaca and Llama side by side
What’s the Difference Between Llamas and Alpacas?
Christmas tree, holiday, pine
How Did the Tradition of Christmas Trees Start?
"Napoleon Crossing the Alps" oil on canvas by Jacques-Louis David, 1800; in the collection of Musee national du chateau de Malmaison.
Was Napoleon Short?
Home
Science
Mathematics
Science & Tech
Gilbert Ames Bliss
American mathematician

Written and fact-checked by
Last Updated: Article History
Category: Science & Tech
Born: May 9, 1876, Chicago
Died: May 8, 1951, Harvey, Ill. (aged 74)
Subjects Of Study: algebraic function ballistics calculus calculus of variations
Gilbert Ames Bliss, (born May 9, 1876, Chicago—died May 8, 1951, Harvey, Ill.), U.S. mathematician and educator known for his work on the calculus of variations.

He received his B.S. degree in 1897 from the University of Chicago and remained to study mathematical astronomy under F.R. Moulton. He received his M.S. degree in 1898 and two years later his doctorate. Bliss immediately went into teaching as an assistant professor of mathematics at the University of Minnesota from 1900 to 1902, followed by a two-year assistantship at the University of Chicago, a year at the University of Missouri, and three years (1905–1908) as preceptor at Princeton University—a period in which he also served as an editor of the Annals of Mathematics. In 1908 Bliss returned to the faculty at the University of Chicago as an associate professor; he was named professor five years later. He became department chairman in 1927 and served until his retirement in 1941.

Equations written on blackboard
Britannica Quiz
Numbers and Mathematics
Bliss applied his knowledge of calculus to the field of ballistics during the latter days of World War I, when he designed an improved set of firing tables for artillery. His book Mathematics for Exterior Ballistics (1944) was based on this work. His research in algebraic functions led to his paper “Algebraic Functions and Their Divisors,” and Bliss expanded on this work in his book Algebraic Functions (1933). Bliss’s extensive study of the calculations of extreme values of an integral or function culminated in 1946 in his major work, Lectures on the Calculus of Variations. Bliss served as president of the American Mathematical Society from 1921 to 1922.

This article was most recently revised and updated by Amy McKenna.

Gmail

Aushvintas

Tobulinimas Vienam.