1. Car Safety
NEED PRACTICE QUESTIONS

2. Driving Test
How far will a car travel (in meters) if it brakes while traveling at 30 mph?
23m

3. Driving Test
How far will a car travel (in meters) if it brakes while traveling at 70 mph?
96m

4. Driving Test
How far will a car travel (in meters) if it brakes while traveling at 40 mph?
36m

5. Driving Test
How far will a car travel (in meters) if it brakes while traveling at 20 mph?
12m

6. Momentum Select and recall the equation for momentum for collisions
Use the conservation of momentum to solve collision questions
Relate momentum to impulse and force

7. For a particular change in momentum:
Impact Times
When a force acts on an object (changing its movement)
its momentum changes.
Ft = change mv
For a particular change in momentum:
The longer the time the force is applied the lower the force needs to be to get the change in momentum
The shorter the time the force is applied the higher the force needs to be to get the change in momentum

8. Impact Time
So in a collision, if the impact time is short, the force will be high (and so more dangerous and damaging)
In groups: list as many ways as you can that a car is
designed to increase impact time.

9. Air Bags

10. Seat Belts

11. Crumple Zones

12. Stopping Distances
When a driver sees a hazard ahead two things have to happen before they stop in time.
1. They need to think about stopping
2. They need to apply the brakes

13. Stopping Distance = thinking distance + braking distance
The distance the car travels while each of these happens are known as:
the distance travelled while the driver reacts/thinks about stopping
Thinking distance -
the distance travelled from when the brake is applied to when the car comes to a stop.
Braking distance -
Stopping Distance = thinking distance + braking distance

14. Stopping Time The total time it takes for a vehicle to come to a stop
Stopping time = thinking time + braking time
Thinking time = time it takes for the driver to react
Braking time =
time from when the brake is applied to when the car comes to stop

15. READ THE QUESTION

16. Factors that affect stopping distance
Factors that affect thinking distance
Factors that affect braking distance
Some factors affect both thinking and braking distance, some factors effect one or the other.

17. Factors that effect thinking distance
Factors that effect braking distance
Speed
Alcohol/Drugs
Weather/road conditions
Tiredness
Conditions of tyres/brakes
Distractions
Road surface

18. 40 meters apart, placed in accident hotspots!
Driving Test
40 meters apart, placed in accident hotspots!