Natural Laws

1
Chapter 5

• Natural Laws
• and
• Car Control

2
Gravity

• What is gravity?
• the force that pulls things towards the earth
• How does gravity affect you when driving?
• uphill/downhill driving- shift to a lower gear
• What is the center of gravity?
• the point at which an objects weight is evenly
  distributed
• How does center of gravity affect your car and
  its driving ability?
• How will driving uphill and downhill affect your
  stopping distance?
• Which vehicle to the right has the fastest
  stopping ability? why?

High Center of Gravity
Low Center of Gravity
3
Energy of Motion and Stopping Distance
WEIGHT
SPEED

• What 2 things make up energy of motion? (how an
  object moves)
• Depends on speed and weight
• How does speed affect stopping distance?
• SQUARE the change in speed- for example
• double the speed 4 times distance to stop (60
  ft)
• triple the speed 9 times distance to stop (135
  ft)
• How does weight affect stopping distance?
• Double the weight 2 times distance to stop

4
Total Stopping Distance

• Perception Distance the distance you travel
  while identifying a situation
• Reaction Distance the distance you travel from
  the time you identify a hazard and decide to
  brake
• Braking Distance the distance you travel from
  the time you first apply the brakes to a full
  stop

5
Braking Distance

• List 7 factors that affect braking distance-
• speed
• vehicle condition
• road surface
• driver ability
• ABS
• Hills
• Load

6
Traction and Friction

• What controls your car?
• steering wheel
• brake pedal
• accelerator
• 4 tires- most important
• What is friction?
• The gripping action that keeps the tire from
  slipping
• What is tread?
• Allows water to flow away from the tire
• How can you check for TREAD WEAR on your tires?
• What affects your cars traction?
• tread
• inflation of tires

7
Tire Inflation

• More of the tire is touching the surface
• Outer edges of the tire are touching the surface-
  where would you find the most wear and tear?
• Center of tire is touching the surface- where
  would you find the most wear and tear?

8
Banked Curve
Roller Coasters

• Where else would you find a BANKED CURVE?

Race Track

• What is a BANKED CURVE?
• A road built higher on the outside than on the
  inside to keep cars on the road!

9
Motorcycle vs Car
Force of Impact speed weight dist traveled
10
Controlling the Force of Impact

• How hard one moving object hits another object
  force of impact
• Speed Weight Distance traveled force of
  impact
• The most important factor in determining how hard
  an object hits is?
• SPEED- slow down!
• What safety features on
• cars can help control
• the force of impact?
• Show Crash Physics Video

11
SEAT BELT USAGE

• 3 collisions occur in a crash- what are they?
• Turn to the person next to you and discuss if
  YOU THINK THERE SHOULD BE A SEATBELT LAW
  REQUIRING YOU TO WEAR A SEATBELT?
• WHY OR WHY NOT?
• Show seatbelt video

12
Active Restraints

• safety belts
• car seats

Until what age do children have to be in some
sort of car seat?
13
Passive Restraints

• head restraints
• air bags
• bumpers
• side door beams
• reinforced windshield
• steering column
• padded dash

14
Side Impact Collision
Safety features?
15
Crazy Cats
16
Motorcycle Dog
17
I DONT WEAR A SEAT BELT BECAUSE

• I am driving at low speeds most of the time
• I might be saved if I am thrown from the car
• I might be trapped in a burning or submerged car

• I only drive for short trips to stores, school or
  work
• I always ride in the front seat and can brace
  myself against the instrument panel
• I dont think safety belts reduce my chances of
  being injured in a collision