California Teen Driver Education Lesson 4
L4: What should you do to keep your vehicle from rolling away?
- leave your vehicle in a low gear or in "park" if it has an automatic transmission - always engage your parking brake - block your wheels by placing an object in front or behind of the tires
L4: What will the force of gravity do?
- make it easier to stop your car if you are going uphill - make it more difficult to stop your car if you are going downhill
L4: What happens in a crash in regards to the force of impact?
- the kinetic energy of your vehicle and body must be dissipated - the forces needed to dissipate this energy are lower if the time period over which your vehicle moves during the crash is longer - if the car suddenly stops, the forces will be very high
L4: When will understanding the natural forces help you control your vehicle?
- turns - stops - everyday driving conditions
L4: What can friction cause?
- wear - possible destruction of other parts of your vehicle such as bearings and internal engine parts
L4: What may misjudging natural forces do?
- you can be pulled out of a curve and lose control - you may lose traction on wet pavement and be unable to stop - travel too fast to stop quickly in heavy traffic and cause an accident
L4: What does kinetic energy include?
- your body while it is in motion - the loose objects in the car - the car itself
L4: What can stop your vehicle from moving?
- your brakes - the road surface - a fixed object (such as a tree) - another vehicle
L4: What happens when you make a turn?
Centrifugal force pulls your car away from the direction you want to turn and into a straight line
L4: What is the correct way to wear a seatbelt?
In front of the shoulder, snug, and positioned properly
L4: What is the Law of Inertia?
Objects that are moving will continue moving in a straight line and at a constant speed, while objects that are not moving remain at rest, unless acted upon by some other force
L4: Why do cars slow down a hill, moving away from the center of the earth, and roads are "banked in curves to keep the car on the roadway?
The Law of Gravitation
L4: What keeps a car going straight down the highway with minimal steering effort?
The Law of Inertia
L4: What happens during a collision if the seat belt is placed behind the shoulder and rests on the bottom of the ribs?
The body would likely bend at the waist lap belt and all the inertia forces would be focuses on these ribs, breaking them or pushing them into the chest cavity where the lungs and other vital organs can be punctured
L4: What has more momentum- a brick traveling at 10 MPH or a chink of Styrofoam traveling at the same speed?
The brick traveling at 10 MPH
L4: What can banked roadways help you overcome?
The centrifugal force that is pulling you away from the direction in which you want to turn
L4: Why does gravity affect your speed of travel?
The change in gravitational pull as you move towards or away from the center of the earth
L4: What is kinetic energy?
The energy a body possesses because it is in motion
L4: What is potential energy?
The energy that an object possesses because of its position or form
L4: What is momentum?
The force of a moving object
L4: What happens when you drive uphill?
The force of gravity is working against you to slow you down
L4: What is gravity?
The force that pulls all objects towards the center of the earth
L4: What happens if the seat belt is twisted producing a much smaller contact area with the breast bone?
The forces will be focused on this area and, much like a hammer, exerts a large force on a small area
L4: What causes skidding while braking?
The friction of your brakes being stronger than the friction force between your tires and the road, which causes you to lose traction
L4: If centrifugal force isn't actually a force, then what is it?
The inertia of an object going in a straight line
L4: What happens when you and your vehicle are involved in a collision?
The kinetic energy is converted into heat through friction
L4: Why does a head-on collision have the greatest force that stops your car during a crash?
The momentum and kinetic energy of your car absorbs almost instantaneously
L4: What does dissipating the heat do for disc brakes?
The more heat can be used to bring the car to a complete stop
L4: What is needed to do a conversion with the more kinetic energy a vehicle has?
The more heat is required
L4: What is traction?
The result of friction between the road and your tires
L4: What is centrifugal force?
The tendency for objects to be pulled outward when rotating around a center
L4: What is traction caused by?
The weight (gravity effect) of the car pushes the tires to the road due to gravity
L4: Why is it easier to move your hand over fine sandpaper than over rough sandpaper?
There is less friction caused by the surface of the fine sandpaper
L4: Why can vessels in space move really far without much spent energy?
There is very little air acting to slow them down
L4: What happens if the seat belt is worn correctly during a collision?
There may be some bruising, but the body is forced to stop almost instantaneously instead of hitting the windshield or dashboard
L4: What is traction necessary for?
To steer your car
L4: What is necessary to keep from losing control in a turn?
Traction
L4: What causes a "controlled skid?"
When all four wheels are pointed in slightly different directions throughout the turn
L4: What decreases your kinetic energy when you are driving downhill?
Gravity
L4: What decreases your kinetic energy when you are driving uphill?
Gravity
L4: When can kinetic energy of your vehicle not be converted into friction in your brakes?
If your brakes are locked during a skid
L4: How do you acquire kinetic energy from your body and your vehicle as you increase your driving speed?
- absorbed by your brakes, engine compression forces, or other friction in a controlled stop - absorbed by your body, your vehicle's body, and the objects you hit if you are involved in a crash
L4: What should you do to keep a vehicle in a turn without allowing centrifugal force to pull the car out?
- decelerate before the curve - brake gently and gradually while turning - downshift (manual transmission)
L4: What can help avoid excessive wear to the brake pads and clutch?
- do not ride your brakes - do not drive with your clutch partially engaged (depressed) - use your lower gears to slow the vehicle on downhill grades (downshift)
L4: What must the momentum of your vehicle overcome when you make a controlled stop?
- friction force of your brakes - friction force between your tires and the road - compression force of your engine
L4: What are natural forces that act on your vehicle?
- gravity - inertia - momentum - kinetic and potential energy - friction - centrifugal force
L4: What does the absorption of the momentum and kinetic energy result in?
- heat - the deformation of your vehicle - possible injury to your body
L4: What are some road surface changes?
- ice - rain - snow - oil and diesel field buildup - sand or dirt
L4: What does friction do?
- increased by the weight of your vehicle - decreased if your tires are over-inflated or under-inflated - decreased if the tires are worn smooth - affected by the material used to construct the road - affected by the condition of the surface of the road (including factors due to weather)
L4: What are the three wrong ways to wear a seatbelt?
1. Placing behind the shoulder and resting on the bottom of the ribs 2. Having the belt be too loose 3. Twisting the belt which produces a smaller contact area with the breast bone
L4: What were Sir Isaac Newton's famous laws?
1. The Law of Inertia 2. The Universal Law of Gravitation 3. The Law of Motion and Acceleration 4. The Law of Reciprocal Action
L4: How much kinetic energy are you dealing with if you increase your speed from 10 MPH to 50 MPH?
25x times the amount
L4: How much kinetic energy are you dealing with if you increase your speed from 10 MPH to 20 MPH?
4x the amount
L4: How much momentum would your vehicle have if you increase your speed from 10 MPH to 50 MPH?
5x
L4: What is friction?
A force caused by the contact of one surface on another
L4: What should you do when driving uphill?
Accelerate or change to a lower gear to maintain your speed
L4: Who was Sir Isaac Newton?
An English scientist whose discoveries and theories in "nature's laws" lead to Newtonian Physics
L4: What does the Law of Inertia state?
An object in motion will tend to remain in motion, in a straight line and at a constant speed, unless it is acted upon by an outside force
L4: What can energy not do?
Be created or destroyed
L4: What does the friction on your brakes and clutch result in?
Brake and clutch wear
L4: What does applying the breaks do?
Causes friction
L4: What does braking to a stop do?
Converts kinetic energy into heat energy in your brakes through friction
L4: What does the correct way to wear a seat belt do?
Diffuse the forces all along its length
L4: What can disc brakes do?
Dissipate the heat quickly
L4: How much momentum would your vehicle have if you increase your speed from 10 MPH to 20 MPH?
Double
L4: When happens when you drive downhill?
Gravity will cause you to go faster and increase your stopping distance
L4: What happens when you leave a vehicle parked on an incline?
Gravity works to pull your vehicle downhill
L4: What does friction produce?
Heat
L4: What do the natural forces affect regardless of how well your vehicle is designed or how skilled you are at handling it?
How your vehicles handles
L4: When will the forces that stop your car during a crash be the greatest?
If you have a head-on collision with another vehicle or large immovable object such as a bridge, wall, or tree
L4: What causes your body and loose objects in your car to keep moving forward when your vehicle suddenly stops?
Inertia
L4: Where is energy converted?
Into another form of energy
L4: Why is physics important?
It explains the limits of a vehicles capabilities, safety, and operation
L4: What will happen if you come out of a turn with the potential energy built up in the components of your car's suspension system?
It may cause you to swerve
L4: What happens to the momentum and kinetic energy of your vehicle and body when you are in a crash?
It must be absorbed
L4: What happens if the seat belt is too loose?
It will allow the body to move forward at the speed of the vehicle, then suddenly being stopped by the belt snapping against the breast bone
L4: What is the formula for kinetic energy?
KE = 1/2 MV^2 Kinetic Energy = one half the Mass times Speed (velocity) squared
L4: What does friction convert?
Kinetic energy into static (not-in-motion) energy
L4: What happens with greater momentum?
Less stopping power
L4: What can too much speed or too much braking cause?
Loss of necessary traction
L4: What does maximum treat contact equal?
Maximum friction
L4: What are designed to prevent brakes from locking up?
Modern anti-locking braking systems
L4: When driving, what keeps your vehicle moving?
Momentum
L4: What laws are all drivers subject to in regards to any moving or stationary object?
Natural laws and laws of physics
L4: What does the Law of Gravitation state?
One object attracts another, via a straight line, drawn between the objects' center. The larger the mass the stronger the attraction.
L4: What should you do when driving downhill?
Shift to a lower gear or apply your brakes to slow to a safe speed and control your vehicle
L4: Who discovered Calculus?
Sir Isaac Newton
L4: What do air bags do?
Slowly deflates and "catch" your head, allowing it to move forward with slower speeds, preventing impact with the steering wheel
L4: What should you do if you are parking facing downhill
Turn your front wheels towards the curb or side of the road
L4: What should you do if you are parking facing uphill if there is a curb?
Turn your front wheels towards the middle of the road and allow the vehicle to roll back against the curb
L4: What should you do if you are parking facing uphill if there is no curb?
Turn your wheels toward the side of the road
L4: How is friction lowered on the parts by manufacturers?
Using a lubrication system to provide a thin film of oil or grease between the moving parts
L4: What happens due to whiplash?
Using your head restraint mitigates injuries
L4: What helps to stop the vehicle by producing more friction between the tires and the road surface?
Weight
L4: What is the momentum of an object proportional to?
Weight and speed
L4: Where is kinetic energy present?
You and your vehicle
L4: What happens when you are hit from behind while stopped?
Your head tends to stay in place due to inertia while the seat pushes the rest of your body forward
L4: What happens to you if your vehicle suddenly stops?
Your kinetic energy will keep you moving forward
L4: What does gravity affect?
Your speed of travel when you're going uphill and downhill
L4: What do banked roadways improve you on?
Your traction in turns
