Search results
Results from the WOW.Com Content Network
The first equation shows that, after one second, an object will have fallen a distance of 1/2 × 9.8 × 1 2 = 4.9 m. After two seconds it will have fallen 1/2 × 9.8 × 2 2 = 19.6 m; and so on. On the other hand, the penultimate equation becomes grossly inaccurate at great distances.
The gravity g′ at depth d is given by g′ = g(1 − d/R) where g is acceleration due to gravity on the surface of the Earth, d is depth and R is the radius of the Earth. If the density decreased linearly with increasing radius from a density ρ 0 at the center to ρ 1 at the surface, then ρ ( r ) = ρ 0 − ( ρ 0 − ρ 1 ) r / R , and the ...
The preliminary reference Earth model (PREM) plots the average of Earth's properties by depth. [1] It includes a table of Earth properties, including elastic properties, attenuation, density, pressure, and gravity. PREM has been widely used as the basis for seismic tomography and related global geophysical models. [2]
All bodies accelerate in vacuum at the same rate, regardless of the masses or compositions of the bodies; [1] the measurement and analysis of these rates is known as gravimetry. At a fixed point on the surface, the magnitude of Earth's gravity results from combined effect of gravitation and the centrifugal force from Earth's rotation .
A meaningful test on the time-variation of G would require comparison with a non-gravitational force to obtain a dimensionless quantity, e.g. through the ratio of the gravitational force to the electrostatic force between two electrons, which in turn is related to the dimensionless fine-structure constant.
In addition to Poynting, measurements were made by C. V. Boys (1895) [25] and Carl Braun (1897), [26] with compatible results suggesting G = 6.66(1) × 10 −11 m 3 ⋅kg −1 ⋅s −2. The modern notation involving the constant G was introduced by Boys in 1894 [12] and becomes standard by the end of the 1890s, with values usually cited in the ...
A relatively simple version [1] of the vertical fluid pressure variation is simply that the pressure difference between two elevations is the product of elevation change, gravity, and density. The equation is as follows: =, where P is pressure, ρ is density, g is acceleration of gravity, and; h is height.
Peak ground acceleration can be expressed in fractions of g (the standard acceleration due to Earth's gravity, equivalent to g-force) as either a decimal or percentage; in m/s 2 (1 g = 9.81 m/s 2); [7] or in multiples of Gal, where 1 Gal is equal to 0.01 m/s 2 (1 g = 981 Gal).