Ikco DONG FENG S30 2016 Owner's Manual page 43

SAFETY BELT
1
The passenger not wearing the safety
belt is not "bundled" up with the vehicle.
When the vehicle decelerates suddenly
in front of obstacles or suffers a front
collision, the passenger
moving at the speed before acceleration
or collision and bump into such interior
components as steering
instrument panel, front windshield or
even be thrown out of the vehicle,
endangering the life.
42
The vehicle speed is the most significant
factor during collision. For instance, if
the vehicle speed increases to 50km/h
from 25km/h, i.e. doubled, the kinetic
will keep energy will be quadrupled.
When the vehicle runs at the speed from
30km/h to 50km/h, the force applied on
wheel, human body during accident is easy to
surpass 10,000 N, equal to a mass of 1t
(1,000kg).
If the passenger does not wear the
safety belt, all of his/her kinetic energy
during the collision accident can only
be absorbed by his/her body and the
collided objects. With the increase
of vehicle speed, the force exerted
on human body will be geometrically
multiplied against the vehicle speed.
It means that, if the vehicle speed is
doubled, the impact on human body will
be quadrupled.
However, if the safety belt is fastened,
the kinetic energy will be damped and
mitigated by the safety belt, substantially
reducing the force applied on the human
body and transferring the force to the
body part with strong bearing capacity,
thus reducing the risk of personal injury.
Some people think that the body can be
supported by hand during slight collision.
It is absolutely wrong. The force applied
on human body can never be supported
despite a low collision speed.