Drivers Ed Chapter 9

Gravity

Gravity

force pulling all objects to the center of earth

center of gravity

point at which an objects weight is evenly balanced

True or false: Having a lower center of gravity allows for better control

True

car going uphill

center of gravity is more towards back tires. your speed should increase to make sure you get over the hill.

car going downhill

center of gravity is more toward front tires (could cause you to roll over). your speed should decrease since you are going downhill.

effects on center of gravity

-height of vehicle -the speed you take going into a turn -weight of vehicle -width of car/wheel base

the faster your car is moving,

the more energy of motion it has (means harder to control)

if a vehicle has double the weight, its stopping distance...

doubles

if it is going double the SPEED, its stopping distance...

quadruples

if it has double weight and speed, its stopping distance is...

9 times

friction

a gripping action -Three types (rolling=tires and car are moving, sliding=car is moving but tires are not (skid), standing=neither are moving)

traction

friction created by the tires an the roadway

tread

pattern on a tire that is used to push water away

underinflated tire

outside edges wear

overinflated tire

center of tire wears

True or false: Traction is better whenever you speed up for a turn.

False. Traction will be better if you slow down when turning.

Factors that reduce traction

1. Poor car conditions (bad shocks or tires)

2. Poor road surface

How to check for traction

1. Make sure no traffic is around you

2. Brake gently to see how your car responds

3. Reduce speed if your car does not respond well

Factors that effect control in a turn/ curve

1. speed

2. sharpness of the curve

3. bank of the curve

4. load or weight of your vehicle

3 steps for stopping distance

Perception (seeing), reaction (time that starts as soon as you take foot off gas), braking (as soon as foot hits the brake pedal)

factors that reduce ability to see

weather, sun galre, other cars and their headlights, phones, dark outside, dirty windshield, alcohol and drugs, tired, glasses or having bad vision, your emotions

factors that reduce ability to react

injury or disability, type of shoes, cruise control, lack of sleep, food on lap, age, panic

factors that reduce ability to brake

faulty brakes, snow, ice, bad tires, wet leaves, speed, weight, distance

Force of impact

Faster speed=harder hit Heavier weight (of either car or object)=harder hit Distance from impact to stop=hit something softer or moveable

List the 7 energy obsorbing features (how your car protects you in a collision)

1. Airbags

2. Seatbelts

3. Crush zones

4. Energy absorbing bumpers

5. Side impact panels

6. Penetration restraint windshield

7. Head restraints