26 résultats pour "pulls"
-
Gravitation
I
INTRODUCTION
Gravitation, the force of attraction between all objects that tends to pull them toward one another.
precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...
- LE PULL-OVER ROUGE
-
Swimming.
the swimmer and the pinky finger should enter the water first. At the same time, the swimmer moves the left arm through the water below the left side of the body.Once in the water, the right arm begins pulling the swimmer forward by bending at the elbow. At the same time the swimmer holds the left arm straight as it reachesthe hip and lifts it out of the water. As the right arm continues to pull, the swimmer rotates slightly onto the right side and swings the left arm up above the head. As the s...
-
Plate Tectonics.
ridges. The Mid-Atlantic Ridge is an underwater mountain range created at a divergent plate boundary in the middle of the Atlantic Ocean. It is part of a worldwidesystem of ridges made by seafloor spreading. The Mid-Atlantic Ridge is currently spreading at a rate of 2.5 cm per year (1 in per year). The mid-ocean ridges today are60,000 km (about 40,000 mi) long, forming the largest continuous mountain chain on earth. Earthquakes, faults, underwater volcanic eruptions, and vents, oropenings, along...
-
Neptune (planet) - astronomy.
The gaseous atmosphere of Neptune contains hydrogen, helium, and about 3 percent methane. It extends about 5,000 km (about 3,000 mi) above the planet’s ocean.Light reflected from Neptune’s deep atmosphere is blue, because the atmospheric methane absorbs red and orange light but scatters blue light. In 1998 astronomersalso identified molecules of methyl in Neptune’s atmosphere. Methyl molecules each contain one carbon atom and three hydrogen atoms. Methyl molecules are knownas hydrocarbon radical...
-
Fishing.
directly to the spool and turns the spool one rotation at a time. C Fishing Lines Fishing lines serve as the link between the angler’s reel and the lure or bait. The most popular line used for sportfishing is monofilament nylon line, which is strong anddurable and has a certain amount of stretch, which helps when an angler sets the hook. The line comes in a variety of strengths, from 2-pound test to more than 100-pound test. (Pound test is the amount of pressure that can be put on a line before...
-
Gravitation - astronomy.
precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...
-
Comparative Anatomy.
In comparing two species, anatomists have to be careful to differentiate between homologous structures, which are ones that have evolved from a shared ancestor, andanalogous structures, which have developed from different origins. Homologous structures are built on the same underlying plan. A human arm, a bat’s wing, and awhale’s flipper look quite different from the outside, but the bones inside reveal that these limbs all have the same basic structure. Analogous structures, by contrast,often l...
-
-
Machine
I
INTRODUCTION
Machine, simple device that affects the force, or effort, needed to do a certain amount of work.
to decrease the amount of force needed to do work or to change the direction of the force. The wheel and axle and some levers can also be used to increase the speedof performance of a task, but doing so always increases the amount of force needed. A Inclined Plane NutsNuts are pieces of metal with a hole in the middle. They are screwed on the end of a bolt as a fastening. Nuts come invarying shapes, depending on their intended use.© Microsoft Corporation. All Rights Reserved. Ramps and staircas...
-
Orthographe
Accords des adjectifs
Tu accordes l'adjectif avec le nom
(neuf)
(beau)
des pulls _____________
un
Orthographe Accords des adjectifs Tu complètes par un adjectif de ton choix et tu accordes comme il convient De ………………… flocons ………………… commencent à tomber. Magali a acheté une ……………………… robe ………………………… . Magali a trois …………………………. Chats …………………………… . Mon papa a une ……………………………… voiture ………………………. . Ces petits chats ont des ………………………….. oreilles ……………………………. . Orthographe Accords des adjectifs Tu complètes avec l’adjectif entre parenthèses (nouveau) l’année ……………………………………………………………. Un ……………………...
-
Saturn - astronomy.
measurements of the magnetic field made by the Voyager space probes in the 1980s. Additional Cassini findings reported in March 2007 suggested that particles originating from geysers on the moon Enceladus may provide a partial explanation for thechange. The neutral gas particles become electrically charged and are captured by Saturn’s magnetic field, forming a disk of hot, ionized gas around the planet’sequator. The charged particles interact with the magnetic field and slow down the rotation of...
-
problèmes
Identifier des données manquantes
Lis les énoncés suivants puis réponds aux questions
Pour partir aux sports d'hiver, Mélanie achète une paire de skis valant (129?);
une paire de chaussures valant (69?); un pull vendu (20 ?); une paire de gants
et un bonnet.
problèmes Identifier des données ma nquantes Lis les énoncés suivants puis réponds aux questions Pour refaire la chambre d'Éric, ses parents ont acheté 6 rouleaux de papier peint à (11Є) le rouleau, deux paquets de colle valant (8Є) le paquet et deux pots de peinture. Calcule, en F, la dépense totale. Fais un schéma afin de repérer la donnée manquante.
-
Hydrogen - chemistry.
Hydrogen gas does not usually react with other chemicals at room temperature. That is, it does not split into two hydrogen atoms to combine with other chemicals. Thebond between the hydrogen atoms is very strong and can only be broken with a large amount of energy. However, when heated with a flame or a spark, hydrogen gaswill react violently with oxygen in the air to produce water in the following reaction: 2H2 + O 2 → 2H 2O This chemical equation shows that two hydrogen molecules (H 2) and o...
-
Horse - biology.
Horses reach sexual maturity at about one and a half years. The estrous cycle in the mare—a mature female horse—typically lasts 21 days. During the first five days ofthe cycle, the mare is usually receptive to mating. The estrous cycle stops during winter and resumes in the spring, which is the start of the breeding season. Astallion—a mature male horse—approaching a mare in estrus engages in various courtship rituals. These include uttering nickering sounds and sniffing and licking themare’s ge...
-
Extrasolar Planets - astronomy.
When a planet passes in a front of the star it orbits—an event called a transit—it causes a small dip in the brightness of the star. Measuring the slight change in thebrightness can be used not only to directly detect a planet, but to determine its size and orbit. However, the planet needs to orbit in a plane that lies in a telescope’sline of sight on the star. Despite long odds, Earth-based telescopes have detected and studied a few exoplanets using this method. The first space telescope design...
-
CE 26 juillet 1985, Ville d’Aix-en-Provence c/Société Gaumont Distribution
commission doit donner des autorisations pour que les films puissent être diffusés sur le territoire national. Cette commission a vu élargir ses pouvoirs en 1936, puisqu’elle donnait ses autorisations en vertu d’un certain nombre de critère comme l’intérêt national, l’intérêt de la défense des bonnes mœurs et le respect des traditions nationales. Cette commission se compose de professionnels du cinéma et de représentants du ministère, des représentants du ministère de la Justice, de l...
-
-
Macroeconomics.
IV INFLATION For several decades after World War II (1939-1945) the main inflation theories were demand-pull and cost-push. The cost-push theory basically emphasized the role ofexcessive increases in wages relative to productivity increases as a cause of inflation, whereas the demand-pull theory tended to attribute inflation more to excessdemand in the goods market caused by expansion of the money supply. A central concept in inflationary theory since the mid-1950s has been the Phillips curve...
-
Supernova - astronomy.
The term hypernova has been proposed for an extremely massive core-collapse supernova—possibly more than 100 times the mass of the Sun. A hypernova is thought to form a black hole. Just before it explodes, a hypernova may release a huge burst of gamma rays in a jet from the rotating black hole at its center. These jets mayexplain the so-called long gamma-ray bursts detected by astronomers. According to some researchers, massive stars with over 40 solar masses may sometimescollapse directly int...
- Stratégie de communication
-
Redshift - astronomy.
Astronomers can also use redshift to identify the oldest and most distant objects in the observable universe. Astronomers believe that quasars are the most distantobjects in the universe, because they have some of the largest redshifts. Quasars are objects in space that strongly emit radio waves. Astronomers originally namedthese objects quasars, which stands for quas i-stell ar (or starlike) radio source, because they appear as points of light, like stars, in photographs of the sky. When astro...
-
Galaxy - astronomy.
Astronomers have obtained images of young galaxies using the Keck Telescope in Hawaii and the Hubble Space Telescope, which resides in an orbit high above Earth’satmosphere and thus avoids atmospheric interference. Photos from the HST show galaxies that are as far as 13 billion light-years away from Earth, which means theyformed soon after the universe formed about 13.7 billion years ago. The galaxies appear to be spherical in shape, and may be early precursors of elliptical and spiralgalaxies....
-
Astronomy - astronomy.
Telescopes may use either lenses or mirrors to gather visible light, permitting direct observation or photographic recording of distant objects. Those that use lenses arecalled refracting telescopes, since they use the property of refraction, or bending, of light ( see Optics: Reflection and Refraction ). The largest refracting telescope is the 40-in (1-m) telescope at the Yerkes Observatory in Williams Bay, Wisconsin, founded in the late 19th century. Lenses bend different colors of light by d...
-
Mountain Climbing.
teeth on one side, and a straight, flat, metal blade called an adze on the other. Ice axes have many uses. One of the most common is to help the climber stay balanced on steep slopes. The climber swings the axe with a short, quick movement to lodge the pick in snow or ice, creating a secure anchor. If a climber should slip and beginsliding down a snowfield, a self-arrest can be performed by turning face down on the snow and burying the pick in the snow surface. The climber’s weight over the...
-
Comet - astronomy.
may exceed the planet Jupiter in size, however. Observations from telescopes on Earth and in space indicate that most of the gases in the coma and tail of a comet are fragmentary molecules, or radicals, of the mostcommon elements in space: hydrogen, carbon, nitrogen, and oxygen. The radicals, for example, of CH, NH, and OH may be broken away from the stable molecules CH 4 (methane), NH 3 (ammonia), and H 2O (water), which may exist as ices or more complex, very cold compounds in the nucleus. Al...
-
-
History of Astronomy - astronomy.
Egypt, the Sun was directly overhead at noon. On the same date and time in Alexandria, Egypt, the Sun was about 7 degrees south of zenith. With simple geometryand knowledge of the distance between the two cities, he estimated the circumference of the Earth to be 250,000 stadia. (The stadium was a unit of length, derivedfrom the length of the racetrack in an ancient Greek stadium. We have an approximate idea of how big an ancient Greek stadium was, and based on that approximationEratosthenes was...
-
Planetary Science - astronomy.
III ORIGINS AND COMPOSITIONS OF PLANETS Astronomers believe that planetary systems are formed of elemental materials that were created in the interiors of giant stars. Some of this material comes from giantstars that shed material into space as they age. Most of the matter to form planets, however, comes from stars that explode as supernovas and spread debris enrichedwith the heavier chemical elements into space. According to the currently accepted views, the most likely first stage in the evo...