Studied by 72 peopleReaction time
The time it takes to respond to a situation
Random errors
Errors that cannot be corrected by calculator
Systematic errors
Errors that can be corrected by calculation
Accuracy
How close a series of measurements are to an accepted value
Precision
How close a series of measurements are to each other
Speed
The distance traveled per unit time
Constant speed
Speed that does not change over a period of time
Average speed
The total distance traveled divided by the time it took to travel that distance
Instantaneous speed
The speed at a given moment
Velocity
Speed in a given direction
Doppler effect
The change in the pitch or frequency of a sound for an observer that is moving relative to the source of the sound
Reaction distance
The distance that a vehicle travels in the time it takes the driver to react
Initial speed
The speed at which you begin to apply the brakes
Breaking distance
The distance required to bring the vehicle to rest once the breaks are applied.
Stopping distance
Minimum distance required to stop a vehicle in an emergency
Acceleration
The change in velocity with respect to a change in time
Vector
A quantity that has both magnitude and direction
Negative acceleration
A decrease in velocity with respect to time
Positive acceleration
An increase in velocity with respect to time.
Force
An interaction between two objects that can result in an acceleration of either or both objects.
Pressure
Force that is spread out over a given area
Kinetic Energy
The energy possessed by a moving body
Law of conservation of momentum
The momentum before a collision is equal to the momentum after a collision
Newton's third law of motion
If object A and object B collide, the force of object A and B will be equal and opposite to the force of object B on A.
Newton's First Law
An object in motion will stay in motion at a constant speed and travel in a strait line unless a force acts on it.
Newton's Second Law
If a body is acted on by an unbalanced force it will accelerate in the direction of the unbalanced force. (The smaller the mass, the bigger the acceleration.)
Inertia
The natural tendency of an object to remain at rest or to remain moving with constant speed in a straight line.
First collision
Vehicle hits an object and comes to a stop or slows down.
Second collision
People in the vehicle will continue to move at the same speed until they are stopped by the interior parts of the vehicle.
Third collision
The brain and body organs are also moving at the speed and will continue to move until the shell of the body is stops them.
Work
The amount of force applied on an object over a certain distance
Does work equal the change in kinetic Energy? True/False
True
Whiplash
The common name for a type of neck injury to muscles of the neck
What is the unit of work?
Joule
What is the unit of pressure?
Pascals
What is the unit for kinetic energy?
Joule
What is the unit for momentum?
kg*m/s
What is momentum?
The product of the mass and the velocity of an object; momentum is a vector quantity
What is impulse?
A change in momentum of an object
What is the unit of force?
Newtons
What is unbalanced force?
It is the force applied in one direction is greater than the force applied in the opposite direction.
What is a overlap zone?
It is where the GO zone and STOP zone overlap, and the driver has a choice to either stop or go safely.
What is the Dilemma Zone?
It is where there is a gap between the GO zone and STOP zone.
Does a good intersection have a Overlap Zone or Dilemma Zone?
Overlap Zone
What is the STOP zone?
It is all positions where the automobile can safely stop before reaching the intersection
The width and the yellow-light time has effect in the STOP zone? True or False
False
What is the GO zone?
It is all positions where the automobile can safely make it through the intersection when the light turns yellow.
Breaking (negative) acceleration and the driver’s reaction time have no effect in the GO zone?
True
What is the SI unit of length?
Meter
What is the SI unit of mass?
Kilogram
What is the SI unit of time?
Second
What is the SI unit of temperature?
Kelvin
What is the SI unit of current?
Ampere
Work only increases kinetic Energy. True or False
False
If you double your velocity, your kinetic energy is quadrupled? True or False
True
The greater the stopping distance, the greater the force applied over the distance. True or False
False
Momentum is a vector quantity. True or False
True
It is possible for an object to lose inertia. True or False
True
An objects mass does not affect its inertia. True or False
False
The speed of the car has a effect on the reaction time of a person driving the car. True or False
False
Two equal-mass safety dummies are being used to test seat belts. Dummy A has a wide seat belt and Dummy B has a narrow seat belt. Both dummies are crashed into a barrier while in the same car. Which statement below best describes the forces needed to stop each dummy?
Dummy B’s force is bigger than Dummy A’s
Whiplash is most prominent in which type of collison?
Rear-end collisions
A constant net force of 20 N acts on an object of mass 5 kg. As the mass of the object is increased, the acceleration of the object will do what?
Decrease
F=ma is in what law of Newton?
Newton’s second law of motion
Note
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