  In the framework of a model based on the gravitational field of the Kerr
black hole, we turn to investigate the kinematic behavior of extragalactic
jets. We analytically calculate the observable velocities and accelerations
along any geodesic. Then, by numerical calculations, we apply our results to a
geodesic, typical of the M87 jet, and probe our results by confrontation to
recent observations. A transition from non-relativistic to ultrarelativistic
speeds at subparsec scale is highlighted. This transition comes sooner and more
abruptly than in models based on magnetic paradigm, which indicates that we
need a weaker magnetic field to explain observed synchrotron radiation. We
attribute the ejection phenomenon to the repulsive effect of the
gravitomagnetic Kerr field.
