Driver's Education-Chapter 9 Natural Laws
momentum
Tendency of an object to stay in motion, or the inertia of an object in motion
Friction
The force between the tires and the road
Too much air
The tire is called Overinflation, which causes only the center of the tire to grip the ground, therefore the footprint is SMALLER and the tire will wear out more QuickLY
Grip
The traction of the tires enable your car, in order to slow your vehicle or move it forward
True or False, A SUV, pickups and vans have a higher center of gravity so they are less stable
True
Speed affects the force of impact
Try to reduce speed in an emergency
Roll
Vehicle that tip to the side, can cause the vehicle to __________The greater your speed, and the harder you steer
More stable center of gravity
Vehicles that are close to the ground are more stable and less likely to roll over
Headrests are designed to prevent
WHIPLASH injuries
Speed
Momentum increases with speed, thus more traction is needed
energy of motion
a moving object is called this or kinetic eergy
How to wear a safety belt
1. Adjust seat to upright position and make sure belt is not TWISTED 2. CLICK the safety belt latch into the buckle 3.Snug around hips, and touches the thighs 4.Adjust the shoulder belt snugly across your CHEST and COLLARBONE
Most efficient way to stop
A straight line which allows the braking fore to be distributed to all four tires
Blowout
A worn, bald tire is dangerous and will not grip a wet or icy road. Because it has no tread, the tire can be easily be punctured, when all the air escapes at once.
perception distance
About 3/4s of a second, is the distance your vehicle travels during your perception time
The time between impact and stopping affects the force of impact
Because a a vehicle suddenly hits a brick wall, major damage But if a vehicle is hits a barrels of sand or bushes before impact its a gradually process that can reduce injury
Other Protective Devices
Crush Zones Energy Absorbing Bumpers Side Impact Panels Penetration-resistant windshields Head Restraints
total stopping distance
Distance the car travels from the time you PERCEIVE the hazard to the full stop See figure 8, page 173
Doubling the weight
Doubles the energy of motion and stopping distance
Factors that affect braking
Driver ability Speed Vehicle Conditions Roadway surface Hills Weight of the vehicle's load
Proper Traction
Gives the maximum traction and maximizes the life of the tire.
Downhill
Gravity will make vehicle go FASTER
Tread
Grooved surface of a tire
Side Air BAGs
Protect the head and chest in a collision, especially to help ejection or a rollover
More traction
Is needed around sharp curves
BEFORE
It is best to check the tire pressure, always________start driving.
Doubling speed
Makes four times the energy of motion and the distance to STOP
Yaw
Occurs when a vehicle rotates clockwise or counterclockwise or does a complete spin.
Active Restraint Device
Safety belt, which distributes forces of rapid deceleration over larger and stronger parts of the body, usually is flexible and has a lap and should er strap
Faster
These cars have more momentum
Proper inflated tires
This is important for maintaining traction and control
Not enough air
This is under inflation, which causes the outside edge to provide traction
Pitch
Tilting motion from front to back, such as when you apply the brakes the motion shifts more weight onto the the front tires and less on the rear tires. But when you accelerate, more weight is out on the rear tires and less weight on the front. Changing wieght can increase or reduce traction
When air is COLDER
Tire pressure will drop
Passive Restraint Device
Works automatically is an airbag ( a balloon-type device that automatically inflates to protect you in a collision) also called FRONTAL AIR BAGS
Banked curve
a curve that is tilted on the outside (this type of curve allows the force of gravity to pull the vehicle downward and into the curve.
load
heavy load change the center of gravity and alters the weight distribution of the wheel. You should reduce speed when you are heavily loaded
Heavier weight creates
more damage in a collision
inertia
objects that are rest tend to stay at rest and objects that are moving tend to keep moving
gravity
the FORCE that pulls all things to EARTH
Braking distance
the distance your vehicle travels from the time you apply the brake until you stop. In order to stop your brakes MUST OVERCOME YOUR ENERgy OF MOTION. Braking distance is proportional to the square of your speed. Example 40MPH would be 4 times longer than traveling 20 miles per hour
Reaction Distance
the distance your vehicle travels while you react
Vehicle Balance
the distribution of a vehicle's weight on its tires as they contact the ground
Force of impact
the force with which a moving object hits another object Determined the force of IMPACT-SPEED Weight and Time between initial impact and stopping
Traction
the friction that results from the tire meeting the road surface
perception time
the length of time it take you to identify a Hazard, Predict a Conflict and Decide to brake
Reaction time
the length of time you take to APPLY the BRAKE
Weight and speed
the momentum of a vehicle depends on these two factors
Natural laws
the motion of your vehicle is subject to this scientific law
Center of gravity
the point around which an objects weight is evenly distributed
Inertia and Traction
the two forces that are applicable when you drive through a curve
The vehicle balance is affected
whenever a vehicle accelerates, brakes, or turns, the changing weight on each tires affects the balance
Hot temperatures
will INCREASE pressure and causes overinflation