Relative velocity
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In kinematics, relative velocity is the vector difference between the velocities of two objects, as evaluated in terms of a single coordinate system, usually an inertial frame of reference unless specifically stated otherwise.
For example, if the velocities of particles A and B are and respectively in terms of a given inertial coordinate system, then the relative velocity of A with respect to B (also called the velocity of A relative to B, or ) is
- .
Conversely, the velocity of B relative to A is
- .
If no other system of coordinates is specified, the expression velocity of A relative to B is usually understood as shorthand for the velocity of A in terms of an inertial coordinate system with respect to which B is at rest.
[edit] References
- Alonso & Finn, Fundamental University Physics ISBN 10:0-201-56518-8
- Greenwood, Donald T, Principles of Dynamics.
- Goodman and Warner, Dynamics.
- Beer and Johnston, Statics and Dynamics.
- McGraw Hill Dictionary of Physics and Mathematics.
- Rindler, W., Essential Relativity.