3. Natural Forces Affecting the Automobile

Friction occurs:

1)Between your tires and the road 2)In your brakes when applied 3)In many parts of your engine and transmission (including the clutch, when engaged)

The friction that the clutch creates when released can:

1)Cause loss of traction if released improperly (peeling out) 2)Slow your vehicle down by engaging a lower gear 3)Allow the vehicle to move regularly

To aviod Friction Effects on Vehicle Components you:

1)Do not ride your brakes 2)Do not drive with your clutch partially engaged (depressed) 3)Use your lower gears to slow the vehicle on downhill grades (downshift). Improper lubrication of your engine and transmission will cause excessive friction, which will result in mechanical failure. 4)The friction on your brakes and clutch results in brake and clutch wear.

Centrifugal force's effect on turns:

1)In a turn, your car is subject to centrifugal force, which is pulling your car away from the direction you want to turn and into a straight line. 2)Traction is necessary to keep from losing control in a turn.

Friction is:

1)Increased by the weight of your vehicle 2)Decreased if your tires are over-inflated or are worn smooth 3)Increased if your tires are under-inflated 4)Affected by the material used to construct the road 5)Affected by the condition of the surface of the road (including factors due to weather)

Worn or over-inflated tires will reduce the friction between your tires and the road surface. This results in the reduction of traction needed to:

1)Start smoothly 2)Stop quickly 3)Pull out of a turn or curve without losing control

When you make a controlled stop, the momentum of your vehicle must be overcome by:

1)The friction force of your brakes 2)The friction force between your tires and the road 3)The compression force of your engine

The loss of traction in a stop or turn can be avoided by:

Driving slower and Properly using your brakes

What is Skidding

caused by the friction of your brakes being stronger than the friction force between your tires and the road. This occurrence causes you to lose traction.

The force of gravity increases the effect of kinetic energy as a car moves where

downhill

In a collision, kinetic energy is dissipated into what 2 parts

energy and heat

Potential Energy

energy of a body or a system with respect to the position of the body or the arrangement of the particles of the system.

Kinetic Energy

energy of motion. The motor vehicle becomes a force of motion that cannot be stopped without the inclusion of other forces. This force may be brakes or another object.

If the road is banked...

enter the curve without banking it too high, so that you don't lose control of the vehicle. A good driving practice is to look ahead so that you enter the curve properly and hold the position throughout the entire curve.

Centripetal force can cause a driver to lose control of a vehicle when ...

entering a sharp curve.

Friction

force caused by the contact of one surface with another. It results in the resistance of an object moving over a surface

Momentum

force of a moving object. The momentum of an object is proportional to its weight and speed.

Gravity uphill

force of gravity is working against you to slow you down. You may need to accelerate or change to a lower gear to maintain your speed.

Gravity

force that pulls all objects towards the center of the earth. It can also affect your speed of travel when going uphill and downhill.

Why does "crush zones" do

help reduce the force of impact on the occupants.

Friction Effects on Braking

1)The kinetic energy of your vehicle cannot be converted into friction in your brakes (heat energy) when your brakes are locked as they are in a locked-wheel skid. 2)If the components of your brakes become too hot, they cannot release any more heat and will fail to absorb any more kinetic energy (such as when traveling down a steep hill and using your brakes a lot). 3)The purpose of anti-lock brakes is to prevent your wheels from locking during a quick stop so that your brakes can continue to absorb energy and you can maintain traction.

Friction Effects on Stopping

1)The weight helps in stopping the vehicle by producing more friction between the tires and the road surface. 2)The kinetic energy of your moving vehicle is converted into heat during braking because of the friction of your brakes against your wheels and the friction of your tires against the road.

How do you stop a moving automobile by transferring kinetic energy into heat energy.

Applying the brakes (raking to overcome the kinetic energy turns the energy into friction when braking.)

Why do you want to avoid braking on a curve?

Braking causes tire friction and, along with centripetal forces, could cause the vehicle to pull out of control. If you must brake on a curve, do so gently so that you do not lose control of the vehicle.

Gravity downhill

Gravity will cause you to go faster. Gravity increases your stopping distance. You may need to shift to a lower gear or smoothly apply your brakes to slow down to a safe speed to control your vehicle.

Changes on the road surface due to the following could result in your losing control of your vehicle:

Ice, Rain, Snow, Oil, Diesel fuel buildup, Sand, or dirt

When to park in parked position.

If the driver is driving an automatic transmission vehicle

When to use first gear

If the driver is parking their vehicle on an uphill

Wheel Blocks

If the driver who is parking on an incline does not feel that their vehicle can safely stay parked, then they need to use wheel blocks. Wheel blocks are blocks that can either be of wood, metal, cement. Wheel blocks are suggested if you are carrying a very heavy load, since vehicles are designed to hold only so much weight.

What happens if the car is set properly

If the vehicle is not set properly, gravity will force itself and the vehicle will careen down the incline.

When to use reverse gear

In a standard transmission vehicle, the driver who is parking their vehicle on a downhill

what causes Centrifugal force

It is caused by the inertia of the body as the body's path is continually redirected.

Factors determining force of impact:

Kinetic energy is a combination of the vehicle and occupant weight and the speed the vehicle was being driven at the time of impact. Therefore, during a collision, the greater the speed and load of the vehicle, the greater the impact and its consequences.

How to counteract the effect of gravity

Low gears are used to overcome gravity while driving uphill and downhill.

Means of affecting centripetal force

The operator of a motor vehicle must reduce their speed when entering into a curve. Otherwise, they cannot enter at the right speed or position to follow the centripetal force. This could cause them to lose control of the vehicle.

Purpose of brakes

This will keep the vehicle from rolling away.

How to counteract inertia

Using safety seatbelts prevents or limits the driver and passengers' injuries that could occur from the effects of inertia.

law of inertia

bjects that are moving tend to continue moving and objects that are not moving tend to remain at rest, unless acted upon by some other force.

what happens When involved in a collision

motion is transferred into friction.

Doubling speed does what to kinetic energy

quadruples kinetic energy

Centrifugal force

the apparent outward force that draws a rotating body away from the center of rotation

The faster an object goes....

the longer it will take that object to come to a stop.

What happens when you're in a crash

the momentum and kinetic energy of your vehicle and body must be absorbed. This results in heat, deformation of your vehicle and possible injury to your body.

what happens The more the body resists the impact of an accident,

the more damage it will sustain.

Parking On A Hill (Headed either uphill or downhill and there is no curb)

turn the wheels so the car will roll away from the center of the road if the brakes fail.

Parking On A Hill (Headed uphill)

turn your front wheels away from the curb and let your vehicle roll back a few inches. The back of the front wheel should gently touch the curb. Set the parking brake.

Parking On A Hill (Headed downhill)

turn your front wheels into the curb or toward the side of the road. Set the parking brake.

The force of gravity decreases the effect of kinetic energy as a car moves where

uphill

What happens when you increase your speed from 10 MPH to 20 MPH

you double your car's momentum.

What happens when you increase your speed from 10 MPH to 50 MPH

you increase your car's momentum five times.

The kinetic energy of your moving vehicle determines what?

your ability to stop the car.