Motion Flashcards
Speed
How fast an object is moving; a scalar, which does not give the direction of motion.
Displacement
The change in position of an object; a vector quantity.
Rate of Change
How fast a quantity is changing over time; calculated as average rate of change.
Photogate
A timing device used in motion experiments, in which light - sensitive photocells are attached to a computer.
Ultra-sonic motion
A riming device which emit short bursts of “clicks” of high-frequency sound waves and detects the returning echo; often connected to a computer.
Distance
The total length of a journey along every twist and turn of the path.
Scalar
A physical quantity that has magnitude (size) but not direction.
Time
Describes when an event occurs
Acceleration
How much an object’s velocity changes in a certain time; that is, rare of change of velocity; a vector quantity.
Vector
A physical quantity that has both magnitude (size) and direction.
Velocity
How fast an object’s positioning is changing, that is the rate of change of position; a vectors quantity, with both speed and direction.
Position
An object’s location as seen by an observer from a particular view-point; a vector quantity, with both distance and direction.
Vector diagram
A diagram of two or more vectors, arranged so that the end of vector is the starting point for the next vector (“tip-to-tail”); used to find vector sums.
Linear motion
Motion forward or backward along a straight line path; directions for position, displacing, velocity and acceleration can be indicated using + and - signs; also called one-dimensional motion.
Readability
An instrument’s greatest possible precision of measurement.
Time interval
The duration of an event, calculated as (final time= initial time)
Precision
The amount of information (by significant digits) a measuring instrument provides.
Vector Sum
The result of adding two or more individual vectors together, “tip-to-tail”.
Instantaneous
The value of a quantity at a specific moment; on a graph, that instantaneous slope is measured from a tangent line.
Ticker Timer
A timing device which makes a series of dots on a paper tape as it is pulled through a timer.
Position-Time graph
A graph is which an object’s position is plotted on the vertical axis and time of the horizontal axis.
Conventions
Agreements among scientists to meatier and calculate using the same units and symbols.
