![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/3/37/Relative_motion_man_on_train.gif/640px-Relative_motion_man_on_train.gif&w=640&q=50)
Relative velocity
Velocity of an object or observer in the rest frame of another object or observer / From Wikipedia, the free encyclopedia
The relative velocity, denoted (also
or
), is the velocity vector of an object or observer B in the rest frame of another object or observer A.
The relative speed
is the vector norm of the relative velocity.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/37/Relative_motion_man_on_train.gif/640px-Relative_motion_man_on_train.gif)