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Understand the impact of gravity, energy, and friction on car control. Learn how to adjust power to overcome gravity, manage downhill speed, and optimize traction for safe driving. Explore the importance of tire pressure, tread, and inflation for better traction and stopping distance. Discover how curves, speed, and braking distance are crucial factors in car control and safety.
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Chapter 5 Natural Laws and Car Control
5.1 Gravity and Energy of Motion
__________________ Is the force that pulls all things to Earth.
Driving Up Hills • You will ____________speed unless you use extra power • To hold speed • You must ____________the vehicle’s power to overcome the pulling force of gravity • Easier to ____________!
Driving Down Hills • Gravity will ____________your speed while going down hill. • Will take you longer to ____________! • Always ____________while going down a hill!
____________of ____________ • Is the point around which an object’s weight is ____________distributed. • Lower the center of gravity – the ____________stable the object becomes. • SUVs very ____________especially when you lift them. *Car carriers!
____________of ____________ • The ____________energy or the energy an object has because it is moving. • The faster your vehicle moves, the ____________energy of motion it has. • Energy of motion is also affected by the ____________of the moving object.
Energy of Motion and Stopping Distance • Go to page 93. • When a truck weighs twice as much; it needs about ____________the distance to STOP!
5.2 Friction & Traction
____________ • Is the force that keeps each tire from ____________on the road. • You can feel the same force by rubbing your hands together.
____________ • Friction or gripping power between the ____________and the roadway surface. • Traction makes it possible for your vehicle to ____________the road so you can change speed and direction.
TIRES!!!! • Tires make a huge difference in the way your vehicle performs. • Driving with low pressure in your tires can be the difference between avoiding a collision or hitting something. • We will discuss this very soon!
Tread and Traction • ____________- outer grooved surface of a tire that grips the road. • Tread allows the tire to cut through ____________and grip the road.
Bald tires • ____________ grip the road • More likely to have a blowout. • ____________ • Is where all the air escapes a tire at once.
Inflation and traction • See page 95 • Always check the owner’s manual to find out the best air pressure range to keep your tires at! • Check regularly! • Cold weather – pressure ____________ • Hot weather – pressure ____________
Underinflation • Only the ____________of the tires will grip the ground. • Outside part of tires will wear first which equally short life of the tires. • In emergencies it will not perform properly.
Overinflation • Only the ____________of the tire will grip the road. • The center of the tire will wear more quickly than a normal tire.
Reduced Traction • Vehicle’s condition • ____________ • ____________ • ____________ • ____________
When are the road most slippery? ________________________________________________________________________________________
Curves • Energy of motion and traction will work on your vehicle as you go around a curve. • The energy of motion will try to make your vehicle go ____________in a curve. • ____________the speed = more it will tend to go straight.
Speed and Curves • You cant control the ___________but you can control your ____________. • Reduce your chances of skidding by ____________your speed before entering a curve.
Sharpness of Curves • The sharper a curve, the more traction your vehicle needs to grip the road. • Sharper the curve = ____________ your speed
Banked Curves • A curve that is ____________on the outside than it is on the inside. • Helps to overcome your vehicle's tendency to move to the outside of the curve.
5.3 Stopping Distance
__________ __________ Distance The distance your car travels while you make a stop.
____________ Time • The ____________ it takes to identify, predict, and decide to slow for a hazard. • Perception time will vary depending on: • ____________ • The ____________ of hazard
Perception _________ • The ____________ your vehicle travels during perception time. • Depending on the driving situation this may change.
____________ Time • The length of time you take to execute your action. • Average reaction time is ____________ of a second.
____________ Distance • The distance your vehicle travels while you react.
____________ Distance • The distance you vehicle travels from the time you ____________ the brake until your vehicle ____________. * If you accelerate from 20 mph to 40 mph, your braking distance will be about ______ times longer.
How do you estimate stopping distance? • Pick a fixed object or checkpoint ahead where you think you can stop. • Count _____ seconds. • Check your position. If you reached it, then you can assume that you could have stopped there under ideal conditions. *If you were traveling 65 mph, it would take about 300 ft to stop (length of a football field.)
Factors that Affect Braking Distance • Speed – higher speed ____________ the braking distance • Vehicle Condition – vehicles with worn shocks, ____________, and brakes need longer time • Roadway surface – rain, ____________, ice, dirt, gravel, & ____________ reduce traction
Driver Ability – if you are distracted or impaired, it will take you longer to stop your vehicle. • Antilock Braking System – allows you to better control your stopping distance while turning • Hills – braking ____________ when driving downhill • Loads – ____________loads increase your braking distance
5.4 Controlling Force of Impact
Force of Impact • The force with which a ______________________________________________________ • Three factors that determine how hard something will hit another object: • ____________ • ____________ • ________________________________
Speed • Is the ____________ factor in determining how hard a vehicle will hit another object. • Any reduction in speed will greatly ____________ the damage inflicted. • Always try to ____________ speed in an emergency.
Weight • The heavier a vehicle, the ____________ damage it will cause in a collision. • A vehicle weighing twice as much as another vehicle will hit a solid object ____________ as hard.
Distance between impact & stopping • The ______________ a vehicle covers between the instant it hits an object and the moment it comes to a __________ can vary greatly. • Sand barrels slow your vehicle as it hits a guardrail.
How many collisions occur when you are in a collision? • 1st – The ______________ hits the object and stops. • 2nd – The ______________ either hit the inside of the vehicle or their restraints devices. • 3rd – Occupants may suffer internal collisions as their organs ______________ their bodies.
Passive Restraints Devices • Works ______________ • Ex. ______________
Active Restraint Devices • Is a device that you have to ______________ . • Ex. ______________
How to wear safety belts • Adjust your seat to a comfortable upright position. • Buckle your seatbelt making sure lap part is low and snug across your hips. • Adjust shoulder part. Never put it behind your body!
Air Bags • Is balloon-type device that automatically inflates to protect you. • They deploy at speeds over _______ mph. • Are designed to work with ____________ . • Keep hands between 9 and 3 o’clock and 8 and 4 o’clock to prevent serious hand, arm, head, and eye injury.
Airbags continued… • Make sure you sit at least ______________ inches away from the steering wheel. • Children in child seats and young people up to the age of ______________ must sit in the back seat.
Air bag Improvements • Sensors can measure weight, seat position, and severity of crash. • Deploys in 2 stages appropriate for speed and intensity • Airbag switches give vehicle owners a choice about using an airbag.
Other Protection Devices • Automatic Safety Belts • Make sure you buckle the lap belt • Front and rear crush areas • Designed to ______________ on impact like an accordion • Energy absorbing bumpers • Absorb low levels of impact up to _____ mph without damage
Side door beams • Steal beams built into the side door. • ______________ windshield • Two pieces of glass with a thin layer of plastic in the middle help avoid flying glass. • Energy-absorbing steering wheel • Designed to ______________ when hit.
______________ dash • Can reduce injury in all crashes • ______________ seats • All states require them. Must be used in the back seat. • Head restraints • Padded head rests on top of seat protect against ______________ .
