P3f-crumple zones Flashcards
What is the equation for momentum?
Momentum = mass x velocity
What is the eqiation for force?
Force= change in momentum/time
What is newtons second law of motion?
If there is an unbalanced force, the object will accelerate in the direction of the force. The size of the acceleration is decided by F=ma
What does a sudden change in momentum in a collision result in?
A large force that can cause an accident
What does spreading the change in momentun over a longer period of time do?
Reduces risk of injury since it means there will be a smaller force on tbe body which reduces injury
How can forces be reduced when stopping?
- increase stopping or collision time
- increase stopping or collision distance
- decreasing acceleratiom
What are the typical safety features of modern cars?
- crumple zones
- seatbelts
- airbags
- heating in brakes
Why do seatbelts need to be replaced after a crash?
Theyre not as strong once theyve been stretched
What do crumple zones do?
Change shape on impact, increasing the time taken for the car to stop
What do these safety features do in a crash?
Change shape
Absorb energy
Reduce injuries
What are ABS brakes?
Anti-lock braking system
What happens to cars without ABS?
When a driver brakes hard, ordinary brakes lock the wheels so they cant turn which can cause the car to skid
What do ABS do?
- help drivers keep control of the cars steering when braking hard
- ABS brakes automatically pump on and off to stop wheels locking and preventing skidding
- they can give the car a shorter braking distance which prevents collision with car in front
