Drivers ED ch 9
you feel inertia when:
a car brakes rapidly, a car accelerates rapidly, and when a car drives around a sharp curve.
passive restraint device
a device that works automatically such as an air bag.
active restraint device
a device you must engage such as a safety belt.
high center of gravity
a vehicle high of the ground that tends to bounce a lot and is likely to lose control easily.
low center of gravity
a vehicle with a center of gravity that is close to the ground is more stable and less likely to roll over.
when you drive you use traction to:
accelerate, brake, and steer.
blowout
all the air of a tire escapes at once.
restraint devices
any part of a vehicle that holds an occupant in place during a crash.
natural laws of motion
inertia, momentum, energy o motion, and gravity. In emergency situations these laws can work for or against you.
energy of motion
kinetic energy. the more a vehicle weighs the greater its energy of motion.
as you drive uphill the pull of gravity will cause you to;
lose speed
inertia
objects that are at rests tend to stay at rest and objects that are moving tend to keep moving.
when you drive on an underinflated tire:
only the tires edged provide traction. -an underinflated tire is likely to heat up and fail more quickly than a properly inflated tire.
a _________ inflated tire will grip the road better than an underinflated or overinflated tire.
properly
good _______ ________ and _____ are the lifeline to traction:
shock absorbers tires
hydroplaning
sliding on water
three factors that determine the force of imapact
speed weight time between initial impact and stopping
stopping distance
you must: 1. percieve the hazard in your path of travel 2. react. 3. brake to a safe stop
three things are required to achieve ideal levels of traction:
your vehicle must be in good condition, the road surface must be smooth and clear, and you actions must maximize traction.
your ability to go through a curve will be affected by:
1. the sharpness of the curve 2. speed and weight of ur vehicle 3. the shake of the roadway
all children younger than 13 years old should sit or be carried in the:
back seat
water will freeze in shaded areas and on _____ before it does on regular roads.
bridges
Some vehicles have a ____ surface
crowned.
factors that affect the braking distance
driver ability-use 4 second rule to estimate stopping speed vehicle condition/size roadway surface hills
inertia keeps a parked car at rest. for the car to move it must be acted upon by;
forces produced by the engine.
when you are going downhill, gravity's pull will make you;
go faster
what does gravity have to do with you driving a car?
gravity helps keep the tires in contact with the road- brings everything to earth.
traction makes your vehicle
grip the road so you can control speed and ____.
seat belts should be worn snug across your:
hips, chest, and collar bone. designed to work with an air bagm
in an overinflated tire:
if a tire has too much pressure only the center will grip the road giving it less traction.
The vehicles energy of motion is proportional to the _____ of its speed. If you double your speed your vehicle will have _____ times as much energy of motion and will need ____ times as much distance to stop.
square four four
perception distance
the distance your vehicle travels during your perception time.
braking distance
the distance your vehicle travels from the time you apply the brake until you stop.
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.
friction
the force that acts between materials as they move past each other (like in tires on the road)
gravity
the force that pulls all things to earth. the pull of gravity affects you as you drive up and down hills.
force of impact
the force with which a moving object hits another object
tread
the grooved surface of a tire. tread provides the traction for starting, stopping, and gripping the road. -important in preventing skids and hydroplaning.
reaction time
the length of time you take to apply the brake
the amount of momentum depends upon:
the objects weight and speed. heavy vehicles have more momentum than lighter vehicles.
the footprint is
the place where a tire touches the road.
center of gravity
the point around which an object's weight is evenly distributed -the balance point -but the weight of the car is not evenly distributed.
momentum
the tendency of an object to stay in motion or the inertia of a object in motion.
in corellation with traction, most vehicles today have four-wheel or all-wheel drive:
this is a traction control device in which all four wheels have pulling power.
banked roadway
tilted so that one side is higher than the other. -helps you overcome inertia in a roadway.
along with the steering wheel, accelerator, and brake pedal, which part of your control system is key?
tires!!! the way that your tires interact with the surface of the road is essential to safe driving
friction creates;
traction
when tires roll over the surface of the road they create:
traction
the grooved surface of a tire is called
tread
____ can change the pressure in your tires.
weather. -cold weather can lead to under inflation -hot weather can lead to overinflation.
traction
when tires roll over the surface of the road, they create a form of friction called tration.
padded headrests at the top of seats are designed to protect against:
whiplash injuries
