3.2.2.2Non-directional 4Global radii 4.1Nominal radius 4.2Arithmetic mean radius 4.3Authalic radius 4.4Volumetric radius 4.5Rectifying radius 5Topographical radii 5.1Topographical extremes 5.2Topographical global mean 6Derived quantities: diameter, circumference, arc-length, area, volume 7Published values 8History 9See also 10Notes 11References Eratosthenes methods result in a formula that would look like this: 39,350 = 2 x 3.14 x r, or 6,267 kilometers. Earths radius is usually given as 6378137 meters (equatorial radius), its flattening is defined as 1/298.257223 (WGS84), and thus its polar radius is calculated as 6356752 meters.However, the av. In physics, it is established that the acceleration due togravity, g (in meters/sec 2), at a height h meters abovesea level is given by g(h)= 3.99 *10 14 (6.374* 10 6 + h) 2 where 6.374 * 10 6 isthe radius of the Earth in meters. Last edited on 10 February 2023, at 21:43, International Union of Geodesy and Geophysics, IAU 2006 General Assembly: Result of the IAU Resolution votes, Satellites Reveal A Mystery Of Large Change In Earth's Gravity Field, NASA's Grace Finds Greenland Melting Faster, 'Sees' Sumatra Quake, "Discover-TheWorld.com Guam POINTS OF INTEREST Don't Miss Mariana Trench", "Mean radius, mass, and inertia for reference Earth models", https://en.wikipedia.org/w/index.php?title=Earth_radius&oldid=1138658294, WGS-84 ellipsoid, polar radius of curvature (, WGS-84 ellipsoid, Mean radius of semi-axes (, WGS-84 ellipsoid, Radius of Sphere of Equal Area (, WGS-84 ellipsoid, Radius of Sphere of Equal Volume (, meridional radius of curvature at the equator, This page was last edited on 10 February 2023, at 21:43. in the second fundamental form for a surface (Equation (123) in[11]): e, f, and g are elements of the shape tensor: n Not all deformations originate within the Earth. Yes! The meridional mean is well approximated by the semicubic mean of the two axes,[citation needed]. At what distance above the surface of earth, the gravitational force will be reduced by 10%, if the radius of earth is 6370 Km. close. [ Given you're looking for a simple formula, this is probably the simplest way to do it, assuming that the Earth is a sphere with a circumference of 40075 km. More than 2,000 years ago Eratosthenes compared the position of the Suns rays in two locations to calculate the spherical size of the Earth with reasonable accuracy. The cookie is used to store the user consent for the cookies in the category "Other. R Measured around the poles, the circumference is 40,007.863 km (24,859.734 mi). Learn what is circumference of a sphere, how to calculate the circumference of the Earth with the help of solved examples. There are two principal radii of curvature: along the meridional and prime-vertical normal sections. A model of a helicopter rotor has four blades, each of length 3.4 mm from the central shaft to the blade tip. You also have the option to opt-out of these cookies. Hence, we create models to approximate characteristics of Earths surface, generally relying on the simplest model that suits the need. {\displaystyle r=[r^{1},r^{2},r^{3}]^{T}=[x,y,z]^{T}} Her latest book, "A Travel for Taste: Germany," was published in 2015. {\displaystyle w^{2}=\lambda ,}. Earths circumference is the distance around Earth. According to data taken by 183 high-school classes participating in a World Year of Physics project, "Measure the Earth with Shadows", the radius of Earth is 6563 km, compared to the accepted value for the mean radius of 6371 km. The Magellan expedition (15191522), which was the first circumnavigation of the World, soundly demonstrated the sphericity of the Earth,[28] and affirmed the original measurement of 40,000km (25,000mi) by Eratosthenes. So escape velocity = . He studied in Athens at the Lyceum. w This calculated value became a defining value in 1993. Around 1690, Isaac Newton and Christiaan Huygens argued that Earth was closer to an oblate spheroid than to a sphere. Definition of radius 1 : a line segment extending from the center of a circle or sphere to the circumference or bounding surface. The Earth. How do you find the radius in circular motion? Regarding this, what is the diameter of the Earth in scientific notation? George Jackson is the founder and lead contributor of Physics Network, a popular blog dedicated to exploring the fascinating world of physics. The expedition found that Newton's conjecture was correct:[30] the Earth is flattened at the poles due to rotation's centrifugal force. The cookie is used to store the user consent for the cookies in the category "Other. Using the mathematical formula for calculating the volume of a sphere, it has been estimated that the volume of Earth is roughly 259 billion cubic miles. Physics, 22. The earth is made up of three different layers: the crust, the mantle and the core. Its the only planet with life. This cookie is set by GDPR Cookie Consent plugin. wikipedia article on the Juno spacecraft provides an a great overview of this type of process. The equatorial circumference is simply the circle perimeter: Ce=2a, in terms of the equatorial radius, a. \text{Circumference} = 39,350 \text{\ kilometers}. Initially, the idea of a reference ellipsoid was an ellipsoid that best approximated mean ocean level. What is the radius of Earth in exponential form? When he's not busy exploring the mysteries of the universe, George enjoys hiking and spending time with his family. Analytical cookies are used to understand how visitors interact with the website. Putting in the numbers, you have Dividing both sides by m1 gives you the acceleration due to gravity: Newton's law of gravitation gives you the acceleration due to gravity near the surface of the Earth: 9.8 meters/second 2. Explore Asteroids In Depth Key Science Targets The circumference of the Earth is the length or distance measured around it. Part 4: Computation . = which is different from the precise result by under 1m (4105in) the mean of these two axes. It is 6356.752 km (3949.903 mi) at the poles and 6371.001 km (3958.756 mi) on average. Eratosthenes' methods result in a formula that would look like this: 39,350 = 2 x 3.14 x r, or 6,267 kilometers. Drive one of the meter sticks into the ground in your location in a sunny spot. A cylinder has a radius of 8 meters. Science atlas, our goal is to spark the curiosity that exists in all of us. However, Earth is not quite a sphere. As an example, we will use Eratosthenes measurements. The equation for Keplers Third Law is P = a, so the period of a planets orbit (P) squared is equal to the size semi-major axis of the orbit (a) cubed when it is expressed in astronomical units. Additionally, the radius can be estimated from the curvature of the Earth at a point. It has an average density of 5.5 g/cm3. The typical Earth radius (RE) can also be comparable to about 6,371 kilometers (km) (an SI unit of length), or 3,440 maritime miles (nmi) (a maritime unit of length), or roughly 3,959 miles (mi) or 20,902,231 ft (foot), that are US customary / Imperial units of length. The mathematical expressions above apply over the surface of the ellipsoid. Go farther. The corresponding radius of curvature depends on the location and direction of measurement from that point. Do NOT follow this link or you will be banned from the site! MITs Alan , In 2020, as a response to the disruption caused by COVID-19, the College Board modified the AP exams so they were shorter, administered online, covered less material, and had a different format than previous tests. nasa.gov. [ View this answer. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. The oblateness constant q is given by, where is the angular frequency, G is the gravitational constant, and M is the mass of the planet. Compute the circumference of the Earth using the distance and angle measurements you have. Since pi is an infinite number, the calculations in Step 6 will be more accurate. r Another global radius is the Earth's rectifying radius, giving a sphere with circumference equal to the perimeter of the ellipse described by any polar cross section of the ellipsoid. The accelerationwhich is gained by an object because of gravitational forceis called its acceleration due to gravity. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". This is the outside layer of the earth and is made of solid rock, mostly basalt and granite. ] Calculating Earths Volume Averaging these two numbers yields a mean radius of 6,371.0 kilometers (3,958.7 miles), which in turn yields an approximate value for the volume of the Earth of 1.08 quadrillion cubic kilometers (259 trillion cubic miles). High School Students Measure New Value for Earths Radius to Celebrate World Physics Year. Ans. Your email address will not be published. {\displaystyle e} When identifying the position of an observable location, the use of more precise values for WGS-84 radii may not yield a corresponding improvement in accuracy. h is the transmitting antenna height above the ground,. N b) Calculate the surface free-fall acceleration. January 2023: The Next Full Moon is the Wolf or Ice Moon. Enchanted Learning. In particular, the Earth's meridional radius of curvature (in the northsouth direction) at is: where How did Aristotle know the earth was round? Circumference of the Earth in Meters [6] It is an idealized surface, and the Earth measurements used to calculate it have an uncertainty of 2m in both the equatorial and polar dimensions. Earth's polar radius is 3,950 miles (6,356 km) a difference of 13 miles (22 km). Using the parameters from WGS84 ellipsoid of revolution, a = 6,378.137 km and b = 6,356.7523142km, V = 1.083211012km3 (2.59881011cumi). 6 m0. In the modern age, satellites often provide the most accurate and current information through global imaging. Our Planet radius is really a unit of distance utilized in astronomy and geology. Since Earth is roughly spherical, calculating its volume is relatively simple. 1 Since the estimate by Eratosthenes, many models have been created. Here x is the circumference of the earth. How do you find the radius of the Earth using trigonometry? Example 2. Radius of sun is 695 500 km, so in meters you multiply by 1000. g = GM/r2, Where M is the mass of the Earth, r the radius of the Earth (or distance between the center of the Earth and you, standing on its surface), and G is the gravitational constant.