Presentation on theme: "Idaho Public Driver Education Natural Laws Affecting Vehicle Control"— Presentation transcript:
1 Idaho Public Driver Education Natural Laws Affecting Vehicle Control
2 The natural force that pulls all things to earth GRAVITYThe natural force that pulls all things to earthThe center of gravity is where a body’s mass is ___________Throw a ball into the air and it________Gravity gives objects their ________
3 ENERGY OF MOTIONThe white truck and the dump truck are going the same speed.Which vehicle has more energy of motion?Why?
4 EFFECT OF SPEED AND WEIGHT A vehicle’s energy of motion changes in proportion to the square of the change in speedTo 40mph20mphTakes FOUR times the distance to stopTo 60mph20mphTakes NINE times the distance to stop
5 EFFECT OF SPEED AND WEIGHT To stop a vehicle going 60mph would generate approximately enough heat to boil ½ gallon of water!½ Gallon
6 INERTIA Inertia wants to keep these parked cars at rest. Inertia also wants to keep these moving cars moving.
7 INERTIAWhy, when driving through this curve, does inertia create the sensation that you are being pulled to the outside of the curve?Because you are traveling in a straight line and inertia wants to keep you going in a straight line
8 MOMENTUM Momentum is inertia in motion Momentum is the product of speed and weightA small truck filled with potatoes traveling at 20mph has more momentum that a 3,000 lb car traveling at the same speedAs momentum increases so does the potential for lots of damage in a collision
9 MOMENTUMA 50 lb passenger traveling in a vehicle going 30mph will have momentum.No matter how strong that passenger may be, he will not be strong enough to stop the body’s momentum when the vehicle comes to an abrupt stop during a crash!
10 U think U can bench press an elephant? Some say, “I can brace myself in a wreck”, or “I’m strong enough to hold onto the steering wheel”.U think U can bench press an elephant?
13 FORCES OF IMPACT 1. Speed 2. Weight 3. Duration When two objects collide, 3 factors determine how much force there will be on impact1. SpeedWhen a collision stops a vehicle in a very short time the impact will be greater than if it took a longer time to stop2. Weight3. Duration
14 FRICTION The amount of friction between the surfaces depends on: Friction is the force when two surfaces move against each other and one surface resists the otherThe amount of friction between the surfaces depends on:What the surface is made ofWhat is on the surfaceHow rough or smooth it isHow much force is pushing the two surfaces together
15 FRICTION: 4 Types Friction creates TRACTION 1. Static: The holding force between 2 surfaces2. Sliding: Friction that slows down a sliding object3. Rolling: Friction between the ground and tire/wheel4. Internal: Friction that occurs from resistance to motion within elastic objectsFriction creates TRACTION
16 TIRES AND TRACTIONOnly four small areas underneath each tire holds the vehicle on the road!When the car is not moving, it’s got GREAT (static) traction!
18 Traction PiesIn a hard braking situation, most of the traction is needed for brakingAdd hard steering will result in loss of control
19 FORCE EFFECT ON OCCUPANTS As the car enters a turn, inertial wants to keep the vehicle and occupants going straightThe seat position and seat belts hold the passengers in place through the curve
20 MAINTAINING VEHICLE BALANCE The design balance for a vehicle is only reached when the vehicle is not moving, or is moving in a straight line at a constant speedAs soon as the vehicle accelerates, brakes, or turns, the vehicle balance is changedAs soon as motion occurs, weight transfer on the tires changes the size of the tire patchesGoing up or down a hill, or around a corner, or BOTH at the same time, really puts physics into play!
21 MAXIMUM VEHICLE LOADLoad capacity includes the combined weight of people and cargo that the vehicle is designed to safely handle
23 Maximizing Traction and Control Properly inflated tires not only increase traction, they improve gas mileage and save you money!Tires with plenty of tread help maintain traction!A good suspension system helps keep the tires on the road, maximizing traction!
24 THE THREE COLLISIONS in a CRASH1. Car hits object
25 2. Head hits windshieldBody into steering wheel, dashboard, other passengers, etc.
26 3. Brain hits skullThere’s no airbag inside the skull! If the person lives, the result can be severe brain damage.
27 Protecting your Passengers Should be Your First Priority! Idaho Child Safety Seat LawsRear-facing infant seat – First year of lifeForward-facing infant seat – up to 40 lbs.40 lbs. to age 7 - booster seat.Age 7 – seat beltHead RestraintsProper adjustment to avoid neck injurySeat position
28 Occupant Protection Adjustable Head Restraint Shoulder-Belt Mount Air BagGases Vent OpeningCrash Sensors
29 Adjusting Belts for Proper Fit Lap beltlow across hipssnug across hipsavoids internal injuriesShoulder beltover collar bone and chestavoids shoulder dislocationavoids rib cage damage
30 AIR BAGS Air Bags in Dash or Steering Wheel No passenger under 12 years of age in front seatProtects against head and chest injuriesSpeed of inflation is criticalDriver should adjust seat for minimum 10 inch clearance between chest and steering wheelHand position on wheel should be 9 and 3 or lower.Aim steering wheel at chest not face
31 Like Most Victims, Julie Knew Her Killer… Wear Your Seatbelt!In the front AND back!