1. Chapter 5 Natural Laws and Car Control
Driver’s Education
Chapter 5
Natural Laws and Car Control

2. Gravity Gravity – is the force that pulls all things to the earth
Driving up hill – your vehicle will lose speed. You must increase power to overcome gravity and maintain speed
Driving down hill – your vehicle will pick up speed. You must coast or shift to a lower gear to maintain speed

3. Energy of Motion
Energy of Motion(Kinetic Energy) – is energy acquired when an object moves.
When load weight doubles, energy of motion will double. Then the vehicle will need to twice the stopping distance.
Energy of motion will change in proportion to the square of its change in speed. If speed doubles, you will need 4 times the stopping distance. If speed triples, you will need 9 times the stopping distance

4. Traction Traction – friction created by tired on the road surface.
Friction – is the force of two surfaces in contact, this keeps each tire from sliding off the roadway.

5. Tires Tread – Grooved surface of a tire that grips the road.
When the road is wet the tread allows water to flow through the grooves and away from the tire.
A tire’s ability to grip the roadway will increase with the amount of tread touching the road.

6. Blowout Blowout – is when all the air escapes from the tire at once.
This may happen as a result of the tire being bald or from a puncture

7. Tire Inflation
Each tire is design to work properly at a certain air pressure.
Underinflation – only the outside edges of the tire contact road, can cause uneven tire wear.
Overinflation – only the center will contact the road. Will wear more quickly and decrease traction

8. Reduced Traction Road Surface
Vehicle Condition
Good shock absorbers are important for maintaining traction. Worn shock absorbers will cause your vehicle to bounce of the road.
Worn tires will limit your control.
Road Surface
Wet, Icy, or rough roads can greatly reduce traction.
When road surface is poor reduce speed for more control

9. Checking Traction Check rear zones to make sure no traffic is near.
Brake to see how the vehicles responds.
If your vehicle does not slow or if your antilock brakes start to work then reduce your speed.

10. Vehicle Control in Curves
Speed – to reduce your chance of skidding, lower your speed before entering a curve
Sharpness of Curves – the sharper the curve the more traction your vehicle will need to grip the road. Use slower speeds for sharp turns
Banked Curves – is a curve that is higher on the outside than on its inside. This will help the vehicle grip the roadway better.

11. Vehicle Control in Curves
Load – the greater the load of a vehicle, the slower the vehicle will have to go around a curve.
Vehicles with a high center of gravity will flip easier in curves

12. Stopping Distance
Total Stopping Distance – is the distance your vehicle travels while you make a stop.
This is measured from when you first see a hazard to the point where your vehicle stops.
Reaction Time – the length of time it take you to identify a hazard and begin to slow.
Reaction Distance – this is the distance your vehicle travels during this time.

13. Stopping Distance
Braking Distance – the distance your vehicle travels from the time you apply the brakes until you stop.

14. 3 Second Rule
1. Pick a fixed checkpoint – like a shadow over the road or a sign where you think that you could stop. When the car in front of you passed the checkpoint.
2. Count off 3 seconds: “one-one-thousand, two one-thousand, three-one-thousand, four-one-thousand.”
If you pass the checkpoint before you finish counting you are to close to the vehicle in front of you.

15. Factors That Affect Braking Distance
Speed – the higher your speed to longer your braking distance.
Vehicle Condition – worn tire and shock absorbers takes longer to stop
Road Surface – rain, snow, ice, dirt, wet leaves, and gravel will increase stopping distance.
Driver Ability – if you are distracted or impaired it will take longer to stop.
Hills – when driving downhill stopping distance will increase.
Loads – heavy loads will increase braking distance.

16. Force of Impact
Force of Impact – force with which a moving object hits another object.
Speed – most important factor in determining how hard a vehicle will hot another object.
Weight – the heavier the vehicle, the more damage it will cause.
Distance Between Impact and Stopping

17. Safety Belts
Three collisions occur when a vehicle hits a solid object.
1. Vehicle hits object and stop.
2. Occupant either hits inside of the vehicle or restraint devices.
3. Occupants may suffer internal collision as their organs impact inside of the body.

18. Restraint Devices
Passive Restraint Devices – like an air bag, works automatically.
Active Restraint Device – one you have to engage, like a safety device.

19. Other Safety Devices
Airbags – a balloon like device that inflated automatically to protect you.
Front and rear crush areas – vehicles are now designed to crush on impact.
Reinforced Windshield – to avoid flying glass in a collision, vehicles has laminated windshields.

20. Other Safety Devices
Padded Dash – this can reduces injury in all crashes.
Child Seats – special seats for infants or small children. Must be used in the rear seat and used properly.
Head Restraints – padded head rests on the top of seats to protect against whiplash.