public void setDynamic(Vector3f uniformAcceleration) {
        control.verifyReadyForDynamicMode("put link into dynamic mode");

        setKinematicWeight(0f);
        rigidBody.setGravity(uniformAcceleration);
    }
Immediately put this link into dynamic mode. The control must be "ready".

@param uniformAcceleration the uniform acceleration vector to apply (in
physics-space coordinates, not null, unaffected)
jme3-jbullet/src/main/java/com/jme3/bullet/animation/PhysicsLink.java