relative position
and 
, then vP and vQ are the velocities of P and Q relative to the frame of reference with origin O and vP−vQ is the velocity of P relative to Q. If 
and 
, then aP and aQ are the accelerations of P and Q relative to the frame of reference with origin O, and aP−aQ is the acceleration of P relative to Q. These quantities may be called the relative position, the relative velocity, and the relative acceleration of P with respect to Q.
Position of P relative to Q
These notions are important when there are two or more frames of reference, each with an associated observer.
- probability measure
- probability paper
- probability space
- probability vector
- probable error
- product
- product group
- product moment correlation coefficient
- product notation
- product of inertia
- product rule
- product set
- product space
- program
- progression
- projectile
- projection
- projection
- projective geometry
- projective space
- projective transformation
- prolate
- proof
- proof by contradiction
- proof theory