Rotational velocity decreases linearly to zero with constant angular deceleration. Diffuse injuries can result from acceleration/deceleration injuries. Note however that rotational inertia is a factor only during acceleration (and deceleration/braking). Each deceleration and acceleration of the mass contributes to the momentum of the spacecraft. Most land vehicles rely on friction for acceleration, deceleration and changing direction. Pilots observed that the objects were capable of high acceleration, deceleration and maneuverability. Acute bleeds often develop after high-speed acceleration or deceleration injuries. Lighting was installed approaching interchanges, along with acceleration and deceleration lanes. The rolling stock will be air-conditioned and having capability of acceleration and deceleration. These terms refer to deceleration and acceleration of development, respectively. The units are known for a distinctive whine made during acceleration or deceleration. Empirical data tentatively shows a sharp increase in rotational deceleration about 600 Myr ago. Fuel saving features include adaptive knock control and aggressive deceleration fuel cutoff. For manned missions the steepest entry angle is limited by the peak deceleration. Current observations indicate this deceleration parameter being negative.