Chapter 8 Glossary Terms Flashcards
Displacement
A measurement of the change in position of a moving body; a straight line connecting the start and end points is specified in the terms of length and direction.
Distance
A measurement of how far away objects are
Error
The difference between the value measured and the actual measurement
Gradient
Slope of a hill/line.
Gradient= rise/run
Instantaneous speed
The speed of an object at a particular moment
Precision
How close measured values are to each other
Random error
Error that changes
Reaction distance
Distance moved when reacting to an emergency
Reaction time
The length of time it takes a driver to respond to a hazard
Scalar quantity
A quantity like distance or time that has size but not direction
Speed
The rate of change of distance
Systematic error
Error that always differs by the same amount
Vector Quantity
A quantity like displacement or velocity, that has size and direction
Velocity
The rate of change of displacement
Acceleration
The rate of change of velocity
Air resistance
Friction between the air and a moving object
Terminal velocity
The final velocity that an object falls with no further acceleration possible due to air resistance.
Inertia
The tendency of an object to resist changes in its motion
Newton’s First Law of Motion
An object at rest will always remain this way unless it is acted upon by an unbalanced force; an object that is moving will continue to move in the same manner unless acted upon by an unbalanced force.
Newton’s Second Law of Motion
An object will accelerate in the direction of an unbalanced force acting upon it such that:
F net= m x a
Newton’s Third Law of Motion
For every action there is an equal and opposite reaction.
Efficiency
Measure of the useful energy output of an energy transfer.
Elastic potential energy
energy stored in a stretched or compressed material, like string or an elastic band.
Gravitational potential energy
the potential energy possessed by an object due to its position above the ground
