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For example, the measurement of changes in wind velocity in the atmosphere can be obtained with the help of an anemometer in a weather station or by observing the movement of a weather balloon. The anemometer in the first case is measuring the velocity of all the moving particles passing through a fixed point in space, whereas in the second ...
Delta-v (also known as "change in velocity"), symbolized as and pronounced /dɛltə viː/, as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such as launching from or landing on a planet or moon, or an in-space orbital maneuver.
A space vehicle's flight is determined by application of Newton's second law of motion: =, where F is the vector sum of all forces exerted on the vehicle, m is its current mass, and a is the acceleration vector, the instantaneous rate of change of velocity (v), which in turn is the instantaneous rate of change of displacement.
When the Womersley number is large (around 10 or greater), it shows that the flow is dominated by oscillatory inertial forces and that the velocity profile is flat. When the Womersley parameter is low, viscous forces tend to dominate the flow, velocity profiles are parabolic in shape, and the center-line velocity oscillates in phase with the ...
Rate of change of velocity per unit time: the second time derivative of position m/s 2: L T −2: vector Angular acceleration: ω a: Change in angular velocity per unit time rad/s 2: T −2: pseudovector Angular momentum: L: Measure of the extent and direction an object rotates about a reference point kg⋅m 2 /s L 2 M T −1: conserved ...
There are two main descriptions of motion: dynamics and kinematics.Dynamics is general, since the momenta, forces and energy of the particles are taken into account. In this instance, sometimes the term dynamics refers to the differential equations that the system satisfies (e.g., Newton's second law or Euler–Lagrange equations), and sometimes to the solutions to those equations.
where F ext is the net external force on the body, v rel is the relative velocity of the escaping or incoming mass with respect to the center of mass of the body, and v is the velocity of the body. [3] In astrodynamics, which deals with the mechanics of rockets, the term v rel is often called the effective exhaust velocity and denoted v e. [4]
In contrast to an average velocity, referring to the overall motion in a finite time interval, the instantaneous velocity of an object describes the state of motion at a specific point in time. It is defined by letting the length of the time interval Δ t {\displaystyle \Delta t} tend to zero, that is, the velocity is the time derivative of the ...