Drivers Education Chapter 5 Natural Laws and Car

Driver’s Education Chapter 5 Natural Laws and Car Control

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

Energy of Motion(Kinetic Energy) – is energy acquired when an object moves. n When load weight doubles, energy of motion will double. Then the vehicle will need to twice the stopping distance. n 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 n

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

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

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

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

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

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

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

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

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

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

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. n 2. Count off 3 seconds: “one-thousand, two one-thousand, three-one-thousand, fourone-thousand. ” n If you pass the checkpoint before you finish counting you are to close to the vehicle in front of you. n

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

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

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

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

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

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