Total number of bones in the body – 206 Smallest bone in the body – stapes Longest bone in the body – Femur Smallest long bone in the body – Malleus Most slender long bone in the body – Fibula Largest flat bone in the body – Hip bone Largest sesamoid bone in the body – patella Most actively growing area of long bone – Metaphysis Most vascular area of a long bone – Metaphysis Largest nutrient artery in the body – Nutrient artery of Tibia Commonest site of osteomyelitis in a long bone – Metaphysis All long bone of body lie vertically except – Clavicle All the bones in the body are made up of both compact and spongy bone except – Inferior Nasal concha Commonest site of bone marrow aspiration – Manubrium sternum in adult and iliac crest in children. Most abundant cartilage in the body – Hyaline cartilage Most durable cartilage in the body – Fibro cartilage Commonest congenital anomaly due to defective endochondral Ossification – Achondroplasia Most common site of accessory bones – Lambdoid suture of skull All the long bones in the body follow low of Ossification except – Fibula Commonest congenital anomaly due to defective membranous Ossification – Cleidocranial dysostosis Largest hyaline cartilage in the body – Thyroid cartilage of larynx Largest yellow elastic cartilage in the body – Cartilage of Ear auricle
An object at rest remains at rest, or if in motion, remains in motion at a constant velocity unless acted on by a net external force. An external force is a force originating from outside an object rather than a force internal to an object. For instance, the force of gravity that Earth exerts on the moon is an external force on the moon . The property of a body to remain at rest or to remain in motion with constant velocity is called inertia. Newton’s first law is often called the law of inertia . The inertia of an object is measured by its mass. Example-The motion of a ball falling down through the atmosphere,
Newton’s second law of motion
Newton’s second law of motion or law of acceleration is closely related to Newton’s first law of motion. It mathematically states the cause and effect relationship between force and changes in motion. Newton’s second law of motion is more quantitative and is used extensively to calculate what happens in situations involving a force. Newton’s second law states that the acceleration of an object is directly related to the net force and inversely related to its mass. Acceleration is a vector quantity that is defined as the rate at which an object changes its velocity. An object is accelerating if it is changing its velocity. Riding your bicycle is a good example of this law of motion at work. Your bicycle is the mass. Your leg muscles pushing pushing on the pedals of your bicycle is the force.
Newton’s third law of motion
Newton third law or The law of action-reaction His third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A. example, when you jump, your legs apply a force to the ground, and the ground applies and equal and opposite reaction force that propels you into the air. Engineers apply Newton’s third law when designing rockets and other projectile devices.
This is ashutosh from penser and this time i am not talking about any unusual educational topic or any school project. But this time i have something to share and i want your opinion and your point of view, i want to know that what you think on these types of things.
We usually saw or experienced that now a days, many people are depressed. And we know that they are worried about covid 19 problems and i think this is normal and common in these types of situations
But sometime it is not like that some people are experiencing some another type of pain.
I don’t know about that what are they actually feel but some problems are common and some are highlighted by newspaper and tv news channels and top problems are bullying, abusing, breakup, money problem.
And it is not right that one person feeling that bad and we are chilling, this is not a humanity.
We should take a stand, and try to help or atleast listen to his/ her problem and try to solve them.
we should take some steps and make our enviroment joyful. So we decided that what if we started an online camp where you can discuss your problems and we are trying to solve it and makes you happy .
But right i have no idea about that and i don’t have any kind of knowledge and honesty i don’t know that, this is right or not. I am just trying to make people smile
So if you have any suggestions any query or any thing about this session you can contact me –
Mail – email@example.com
So please if you have anything about this session, please discuss it with me
We can create a smile on somebody’s face and make a better future
The rings of Jupiter, Uranus, and Neptune are made of dust, very tiny pieces of rock, and ice. The rings of Saturn are made of large pieces of ice.
We don’t know for sure where these rings came from. In some cases, the rings have come from dust knocked off of the planets’ moons by meteorite bombardment, but some of them might have come from moons torn apart by the planet’s gravity, or they could have formed as the planets formed.
Saturn’s rings are the most magnificent; they are bright, wide, and colourful. Uranus has thirteen dark rings around it, and Neptune’s rings are also dark, but contain a few bright arcs.
We live on a small planet that circles an insignificant star in a tiny part of a huge, spiral star system—the Milky Way galaxy. The Milky Way was born more than 10 billion years ago and is likely to exist for many more billions of years.
Seeing stars If you live far away from bright city lights, you may be lucky enough to see a faint band of light that crosses the night sky. Ancient observers called it the Milky Way because it looked like a stream of spilled milk in the sky. They had no idea what it was, but the puzzle was solved in 1610 when Galileo turned his telescope on the Milky Way and discovered that it was made up of thousands of stars.
A SPIRAL GALAXY The Milky Way is a barred spiral galaxy, which means it is shaped like a giant pinwheel, with curved arms trailing behind as it turns. The stars in our galaxy all move around the center as the galaxy spins. Our Sun, which is about 28,000 light-years from the center, goes around the galaxy once every 220 million years. Stars near the center take less time to orbit than the Sun.
THE HEART OF THE MILKY WAY The center of the Milky Way is a mysterious place about 600 light-years across. While this is just a tiny part of the galaxy, the core contains one-tenth of all the gas in the galaxy, along with billions of stars. These include the remains of supernovas and bright sources of X-rays, such as binary systems (pairs of objects) that are thought to contain a black hole.
Ancient star streams Not all of the material in the Milky Way lies in a flat disk. Three narrow streams of stars have been found arcing high above the galaxy. They are between 13,000 and 130,000 light-years from Earth and extend over much of the northern sky. The largest stream is thought to be the scattered remains of a dwarf galaxy that collided with the Milky Way.
Baby stars The heart of our galaxy is cluttered with stars, dust, and gas surrounding the black hole. Conditions there are harsh, with fierce stellar winds—powerful shock waves that make it difficult for stars to form. We don’t yet know how stars form there because, until recently, no one could peer through the dust to find newborn stars. In 2009, however, the Spitzer Infrared Observatory found three baby stars, all less than one years million old, embedded in cocoons of gas and dust.
Planet Earth is incredibly previous, about 4.5 billion years or additional, per recent estimates. Most of the evidence for an ancient Earth is contained within the rocks that type the planet’s crust. The rock layers themselves, like pages in a very long and complex history, record the surface-shaping events of the past, and buried among them square measure traces of life that’s, the plants and animals that evolved from organic structures, existing maybe three billion years past.
Conjointly contained in once melted rocks square measure radioactive parts whose isotopes offer Earth with a timepiece. Among these rocks parent isotopes decay at a sure rate to create daughter offspring isotopes. By crucial the relative amounts of parent and daughter offspring isotopes, the age of those rocks may be calculated. Therefore, the results of studies of rock layers (stratigraphy) and of fossils (paleontology), in addition to the ages of bound rocks as measured by atomic clocks (geochronology), indicate a really previous Earth.
Up til now scientists haven’t found some way to discourage mine the precise age of Earth directly from terrestrial rocks as a result of our planet’s oldest rocks are recycled and destroyed by the method of morphology. If there square measure any of Earth’s aboriginal rocks left in their original state, scientists haven’t nonetheless found them. Nonetheless, scientists are ready to confirm the probable age of the system and to calculate an age for Earth by forward that Earth and therefore the remainder of the solid bodies within the system fashioned at a similar time and square measure, therefore, of a similar age.
The of Earth and Moon rocks and of meteorites square measure ages measured by the decay of durable radioactive isotopes of parts that occur naturally in rocks and minerals which decay with half-lives of 700 million to quite one hundred billion years into stable isotopes of alternative parts. Scientists use these qualitative analysis techniques, that square measure firmly grounded in physics and square measure illustrious put together as radiometric qualitative analysis, to live the last time that the rock being dated was either dissolved or disturbed sufficiently to rehomogenize its radioactive ele ments. Ancient rocks exceptional 3.5 billion years in age square measure found on all of the planet’s continents.
The oldest rocks on Earth found to this point square measure the Acasta Gneisses in northwestern Canada close to nice Slave Lake (4.03 billion years old) and therefore the Isua Supracrustal rocks in West Greenland (about 3.7 to 3.8 billion years old), however well-studied rocks nearly as previous also are found within the Gopher State stream depression and northern Michigan (some 3.5-3.7 billion years old), in Swaziland (about 3.4-3.5 billion years old), and in Western Australia (approximately 3.4-3.6 billion years old).
Scientists have dated these ancient rocks employing a range of radiometric strategies, and therefore the consistency of the results offers scientists confidence that the calculable ages square measure correct to among some percent. In Western Australia single zirconium silicate crystals found in younger matter rocks have radiometric ages of the maximum amount as 4.3 billion years, creating these little crystals the oldest materials to be found on Earth to this point. Scientists haven’t nonetheless found the supply rocks for these zirconium silicate crystals.
The ages measured for Earth’s oldest rocks and oldest crystals show that our planet is a minimum of 4.3 billion years in age however don’t reveal the precise age of Earth’s formation. The simplest age for Earth is presently calculable as 4.54 billion years. This price is predicated on previous, plausible single-stage leads (Pb) in addition to the lead ratios in troilite from iron meteorites, specifically the canon Diablo meteoroid. additionally, mineworker al grains (zircon) with uranium-lead (U-Pb) ages of 4.4 billion years have recently been reportable from matter rocks found in western Australia.
The Moon could be a a lot of primitive planet than Earth as a result of it’s not been disturbed by morphology. Therefore, a number of the Moon’s a lot of ancient rocks ar a lot of plentiful. The six yankee Greek deity Project human missions and 3 Russian Luna robotic orbiter missions came back solely atiny low number of satellite rocks to Earth. The came back satellite rocks vary greatly in age, a sign of their completely different ages of forma tion and their sequent histories. The oldest dated Moon rocks, however, have ages between 4.4 and 4.5 billion years and supply a minimum age for the formation of our nearest planetary neighbor.
Thousands of meteorites, that are fragments of asteroids that fall to Earth, are recovered. These primitive extra terrestrial objects offer the most effective ages for the time of formation of the scheme. There are over seventy bound dicot genus of various varieties whose ages are measured mistreatment radiometric chemical analysis techniques. The results show that the meteorites, and so the scheme, shaped between 4.53 and 4.58 billion years old. The most effective age for Earth comes not from chemical analysis individual rocks however by considering Earth and meteorites as a part of an equivalent evolving system during which the atom composition of lead, specifically the magnitude relation of lead 207 to lead-206, changes over time as a result of the decay of radioactive uranium-235 and uranium-238, severally.
Scientists have used this approach to work out the time needed for the isotopes in Earth’s oldest lead ores, of that there are solely a couple of, to evolve from its early composition, as measured in uranium-free phases of iron meteorites, to its compositions at the time these lead ores separated from their mantle reservoirs.
According to scientists at the U.S. earth science Survey (USGS), these calculations lead to associate age for Earth and meteorites, and so the scheme, of 4.54 billion years with associate uncertainty of but one p.c. To be precise, this age represents the last time that lead isotopes were homogenised throughout the inner scheme and therefore the time that lead and U were incorporated into the solid bodies of the scheme. The age of 4.54 billion years found for the scheme and Earth is in keeping with current estimates of eleven to thirteen billion years for the age of the Milky Way Galaxy galaxy (based on the stage of evolution of clod ular cluster stars) and therefore the age of ten to fifteen billion years for the age of the universe (based on the recession of distant galaxies).
Nebula, a type of cloud in space. It is formed by dust particle and gases that present in space. When a star die, it will exploded and spread dust and gases all over in space and when a star start its formation the best gas all around it and make a nebula.
The gas in nebulae is mostly hydrogen and helium.
The spreaded gas and dust start to collect condense and make stars.
Nabulae can be anywhere in space near the stars. Hellix nebula is the nearest nebula to us.
Some nebulae are very large such as approximate diameter of 100 light years.
Nebulae are visible in space but not brighter as stars.
There are different types of nebulae and named on the basis if their shapes such as Skull nebula, Cat nebula, Red Rectangle nebula, etc.
Most of the nebulae have no boundries and these nebulae are called diffuse nebula.
Due to very low in density, nebulae have very low mass. Even an earth size nebula have mass of few kilograms.