Search results
Results from the WOW.Com Content Network
Earth's rotation axis moves with respect to the fixed stars (inertial space); the components of this motion are precession and nutation. It also moves with respect to Earth's crust; this is called polar motion. Precession is a rotation of Earth's rotation axis, caused primarily by external torques from the gravity of the Sun, Moon and other bodies.
Consider a body (for example a fixed volume of atmosphere) moving along at a given latitude at velocity in the Earth's rotating reference frame. In the local reference frame of the body, the vertical direction is parallel to the radial vector pointing from the center of the Earth to the location of the body and the horizontal direction is perpendicular to this vertical direction and in the ...
A schematic illustrating the relationship between motion of conducting fluid, organized into rolls by the Coriolis force, and the magnetic field the motion generates. [53] The Earth and most of the planets in the Solar System, as well as the Sun and other stars, all generate magnetic fields through the motion of electrically conducting fluids. [54]
Because the Earth spins, Earth-bound observers need to account for the Coriolis force to correctly analyze the motion of objects. The Earth completes one rotation for each sidereal day, so for motions of everyday objects the Coriolis force is imperceptible; its effects become noticeable only for motions occurring over large distances and long ...
Ekman number (defined above), which is the ratio between the two remaining forces, namely the viscosity and Coriolis force, is very low inside Earth's outer core, because its viscosity is low (1.2–1.5 ×10 −2 pascal-second [20]) due to its liquidity.
In a similar way to how the force from the table generates this phenomenon of precession in the spinning gyro, the gravitational pull of the Sun and Moon on the Earth's equatorial bulge generates a very slow precession of the Earth's axis (see §Cause). This off-center push or pull causes a torque, and a torque on a spinning body results in ...
The weight of an object on Earth's surface is the downwards force on that object, given by Newton's second law of motion, or F = m a (force = mass × acceleration). Gravitational acceleration contributes to the total gravity acceleration, but other factors, such as the rotation of Earth, also contribute, and, therefore, affect the weight of the ...
F 2. gravitational force by object on earth (upward) F 3. force by support on object (upward) F 4. force by object on support (downward) Forces F 1 and F 2 are equal, due to Newton's third law; the same is true for forces F 3 and F 4. Forces F 1 and F 3 are equal if and only if the object is in equilibrium, and no other forces are applied ...