Idaho Public Driver Education

1 / 31

# Idaho Public Driver Education - PowerPoint PPT Presentation

Idaho Public Driver Education. Natural Laws Affecting Vehicle Control. GRAVITY. The natural force that pulls all things to earth. The center of gravity is where a body’s mass is ___________. Throw a ball into the air and it________. Gravity gives objects their ________. ENERGY OF MOTION.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## Idaho Public Driver Education

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Idaho Public Driver Education

Natural Laws Affecting Vehicle Control

GRAVITY

The natural force that pulls all things to earth

The center of gravity is where a body’s mass is ___________

Throw a ball into the air and it________

Gravity gives objects their ________

ENERGY OF MOTION

The white truck and the dump truck are going the same speed.

Which vehicle has more energy of motion?

Why?

To 40mph

To 60mph

20mph

EFFECT OF SPEED AND WEIGHT

A vehicle’s energy of motion changes in proportion to the square of the change in speed

Takes FOUR times the distance to stop

20mph

Takes NINE times the distance to stop

EFFECT OF SPEED AND WEIGHT

To stop a vehicle going 60mph would generate approximately enough heat to boil ½ gallon of water!

½ Gallon

INERTIA

Inertia wants to keep these parked cars at rest.

• Inertia also wants to keep these moving cars moving.

INERTIA

Why, 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

MOMENTUM

• Momentum is inertia in motion
• Momentum is the product of speed and weight

A small truck filled with potatoes traveling at 20mph has more momentum that a 3,000 lb car traveling at the same speed

As momentum increases so does the potential for lots of damage in a collision

MOMENTUM

A 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!

PITCH, ROLL, YAW

Yaw

Pitch

Roll

FORCES OF IMPACT

When two objects collide, 3 factors determine how much force there will be on impact

1. Speed

When a collision stops a vehicle in a very short time the impact will be greater than if it took a longer time to stop

2. Weight

3. Duration

FRICTION

Friction is the force when two surfaces move against each other and one surface resists the other

The amount of friction between the surfaces depends on:

• What the surface is made of
• What is on the surface
• How rough or smooth it is
• How much force is pushing the two surfaces together

FRICTION: 4 Types

1. Static: The holding force between 2 surfaces

2. Sliding: Friction that slows down a sliding object

3. Rolling: Friction between the ground and tire/wheel

4. Internal: Friction that occurs from resistance to motion within elastic objects

Friction creates TRACTION

TIRES AND TRACTION

Only four small areas underneath each tire holds the vehicle on the road!

When the car is not moving, it’s got GREAT (static) traction!

Traction Pies

In a hard braking situation, most of the traction is needed for braking

Add hard steering will result in loss of control

FORCE EFFECT ON OCCUPANTS

As the car enters a turn, inertial wants to keep the vehicle and occupants going straight

The seat position and seat belts hold the passengers in place through the curve

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 speed

As soon as the vehicle accelerates, brakes, or turns, the vehicle balance is changed

As soon as motion occurs, weight transfer on the tires changes the size of the tire patches

Going up or down a hill, or around a corner, or BOTH at the same time, really puts physics into play!

Load capacity includes the combined weight of people and cargo that the vehicle is designed to safely handle

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!

THE THREE COLLISIONS in a

CRASH

1. Car hits object

Body into steering wheel, dashboard, other passengers, etc.

3. Brain hits skull

There’s no airbag inside the skull! If the person lives, the result can be severe brain damage.

• Idaho Child Safety Seat Laws
• Rear-facing infant seat – First year of life
• Forward-facing infant seat – up to 40 lbs.
• 40 lbs. to age 7 - booster seat.
• Age 7 – seat belt
• Proper adjustment to avoid neck injury
• Seat position

Occupant Protection

Shoulder-Belt Mount

Air Bag

Gases Vent Opening

Crash Sensors

• Lap belt
• low across hips
• snug across hips
• avoids internal injuries
• Shoulder belt
• over collar bone and chest
• avoids shoulder dislocation
• avoids rib cage damage
AIR BAGS

Air Bags in Dash or Steering Wheel

• No passenger under 12 years of age in front seat
• Protects against head and chest injuries
• Speed of inflation is critical
• Driver should adjust seat for minimum 10 inch clearance between chest and steering wheel
• Hand position on wheel should be 9 and 3 or lower.
• Aim steering wheel at chest not face
Like Most Victims, Julie Knew Her Killer…