Chevrolet Captiva C140 Manual page 7

WHY SAFET WHY S WHY S WHY S WHY S AFET AFET AFETY BEL AFET Y BEL Y BEL Y BEL Y BELT T T T T S W S W S WORK! S W S W ORK! ORK! ORK! ORK!
Safety belts cannot work unless they are worn
and worn properly.
Vehicle occupants are injured if the forces
applied to the body's structures are greater
than the body can tolerate without being in-
jured. If a person's body is stopped abruptly,
the forces applied to the body will be high,
whereas if the body is slowed down gradually
over some distance, the forces will be much
lower. Thus, in order to protect an occupant
from injury in a crash, the idea is to give the
person as much time and distance as possible
in coming to a stop.
Imagine a person running at 15 miles per hour
(25 km/h) head first into a concrete wall.
Imagine a second person running at 15 miles
per hour into a wall covered by a 3-foot
(90 cm) thick deformable cushion. In the first
instance the person could be seriously injured
or even killed. In the second, the runner could
expect to walk away uninjured. Why? In the
first instance, the body hit the non-yielding
concrete surface and stopped immediately. All
of the energy the sprinter built up was ab-
sorbed by the structures of the body, not by
the non-yielding concrete surface. In the
second example, the body had exactly the
same amount of energy that had to be ab-
sorbed as in the first example, but it contin-
ued to move into the padding, giving the body
additional time and distance to slow down to
a complete stop as the padding absorbed the
sprinter's energy by deforming.
If a car crashes into a concrete wall at
30 miles per hour (50 km/h), the front
bumper of the car stops immediately, but the
passenger compartment stops more gradually
as the front structure of the vehicle crumples.
The belted occupant is held to the seat and
gains the advantage of the cushion provided
by the crumpling of the front of the vehicle
and the stretching of the safety belt webbing.
That belted occupant's body slows down from
50 km/h (30 mph) to zero over a distance of
90-120 cm (3-4 feet). That belted occupant
also remains properly positioned so that, if the
air bag deploys in a frontal collision, the oc-
cupant might never strike any rigid structures
in the vehicle. The unbelted occupant receives
no such benefit. The unbelted person is not
attached to the vehicle and so that person
continues to travel at the vehicle's pre-crash
SEATS AND OCCUPANT PROTECTION SYSTEMS 1–3
speed of 30 miles per hour (50 km/h) until
striking a hard object at approximately
30 miles per hour (50 km/h) and stopping
abruptly. Even in a frontal collision in which
the air bag deploys, the unbelted front seat
occupant remains at greater risk of serious
injury or death than the properly restrained
front seat occupant. (See "SUPPLEMENTAL
RESTRAINT SYSTEM" in the index)