Parallelogram of velocities

(Mech.)

a parallelogram the diagonal of which represents the resultant of two velocities, forces, accelerations, momenta, etc., both in quantity and direction, when the velocities, forces, accelerations, momenta, etc., are represented in quantity and direction by the two adjacent sides of the parallelogram.

Parallelogram of Velocities

a geometric representation of the law of addition of velocities. For the case of a point in compound motion—that is, motion at a velocity v_rel (relative velocity) with respect to a frame of reference moving at a velocity v_veh (vehicle velocity) relative to a fixed frame of reference—the principle of the parallelogram of velocities states that the absolute velocity of the point is represented by the diagonal of a parallelogram whose sides are the vectors v_rel and V_reh. The principle holds for velocities that are small by comparison with the velocity of light.