Car Safety Flashcards
What does a larger force mean in terms of momentum?
A larger force means a faster change in momentum ( a greater acceleration)
How do regenerative brakes work?
> They put the vehicle’s motor in reverse, with the motor running backwards, the wheels are slowed
> the motor acts as an electrical generator, converting the kinetic energy into electrical energy that is stored as chemical energy in the battery
What is the advantage of regenerative breaks?
Store the energy from braking the car rather than wasting it.
Why is a car crash dangerous?
> because the car will slow down in a very short amount of time, meaning that the kinetic energy has to be converted into other types of energy very quickly and could impact the passengers
> because there is a huge change in momentum over a very short space of time meaning that a large force is experienced
What is the main principle of car safety?
> increase the impact time, which decreases the impact force produced by the change in momentum
What are side impact bars?
> strong metal tubes fitted in the sides of car
> direct the kinetic energy of the crash away from the passengers (e.g. towards crumple zones)
How do seatbelts work?
> increase the time taken for the wearer to stop, decreasing the force felt on the chest because of s change in momentum
> when they stretch they absorb some of the kinetic energy of the wearer
What do airbags do?
Slow the passenger down more gradually
> prevents the passenger from hitting hard surfaces
What are 4 components of car safety?
> crumple zones
> side impact bars
> seat belts
> air bags
What happens when a force acts on an object?
> it causes a change in momentum
How do crumple zones work?
> the kinetic energy of the car is converted into other forms of energy as it changes shape
> it increases the impact time, decreasing the impact force caused by the change in momentum.
