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Cars which are moving have kinetic energy. As energy cannot be created or destroyed,
when a car brakes its kinetic energy is transferred into heat energy, which is transferred
into the surroundings. Modern cars also have safety features that absorb kinetic energy
in collisions. These include:
All these features reduce injuries to the people in the car by absorbing energy when they
change shape. As they deform they increase the amount of time the person takes to
come to a stop. This reduces the acceleration and force on the person, so reducing
The basic idea of a seatbelt is very simple: It keeps you from flying
through the windshield or hurdling toward the dashboard when your car
comes to an abrupt stop.
Airbags can reduce injury because they inflate in a fraction of a
second. Their main purpose is to prevent the passenger or driver
from hitting the interior of the vehicle, or even from being thrown
through the windshield.
Crumple zones are designed so that a car will crumple in a particular way
during impact in order to reduce injury. This absorbs some of the energy
of the impact, preventing it from being transmitted to the occupants.
Different Types of Braking Systems
Every time the car brakes are pressed wasted energy is produced. Energy cannot be destroyed, so
when the car slows down, the kinetic energy that was propelling it forward has to go somewhere. Most
of it simply dissipates as heat and becomes useless. That energy, which could have been used to do
work, is wasted.
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Engineers have come up with a kind of braking system that can recapture much of the car's kinetic
energy and convert it into electricity, so that it can be used to recharge the car's batteries. This system
is called regenerative braking.…read more