REVIEWER Flashcards
TWO METHODS OF MEASUREMENT
Direct and indirect method of measurement
is the process of comparing an unknown
quantity with a known quantity or with a
standard
Measurement
simplest types of quantities & cannot be
reduced further
Fundamental Quantities
amount of molecules or particles in a body
Mass
lapse of one event to another event; duration
Time
quantities that are taken or
formulated from two or more fundamental quantities
Example: Area = LW; V = LWH; d = m/V; speed = d/t
Derived Quantities
has magnitude and appropriate unit
Scalar quantity
has magnitude, appropriate unit and direction
Vector quantity
can be used to make a new
unit larger or smaller than the base
Unit prefixes
practical way of checking
mathematical equations by finding out whether they are
consistent in terms of their dimensions.
Dimensional analysis
there are three basic or fundamental
quantities. These 3 quantities are:
Length (meter)
Mass (kilogram)
Time (second)
denote the dimension of a physical quantit
Bracket
an equation that
shows the equivalent amounts of different units.
Unit Equality or conversion factor
A “short cut” to writing extremely large or small numbers by expressing
them as a number between 1 & 10 multiplied by a power of 10.
Scientific notation
Two kinds of certainty (or uncertainty) in scientific
measurement:
Accuracy
Precision
Concerns how closely a
measurement or series
of measurements
reflects the actual
value.
If the set of measurements
is close to the true or
accepted value
Accuracy
How close several
measurements are
to each other.
The values are close
to one another.
Precision
Two classes of error
Systematic and random error
When the error produced is always of the same sign.
It is committed if the measurement tends to make all
observations too big or too small.
Systematic error
Systematic error classified into three
1.) Instrumental errors
2.) Personal
3.) External
errors that involve some peculiarity or bias of the
observer, like the tendency to assume that the first reading is
correct. This is also committed due to eye strain, fatigues, or
position of the eye in reading the scale.
Personal
errors caused by faulty or inaccurate
apparatus.
Instrumental errors
errors that are caused by external conditions like
temperature, humidity, wind, and vibrations.
External
When positive and negative errors are equally probable to
occur.
These errors are erratic errors that are variations due to a lot of
factors, each of which adds or contributes to the total error.
These factors vary and are unknown
Random error
“If one quantity increases, the
other quantity increases at the same rate. If one
quantity decreases, the other quantity decreases at
the same rate.
Direct proportion
“If one quantity increases, the
other quantity decreases at the same rate. If one
quantity decreases, the other quantity increases at
the same rate
Inverse Proportion
The vector quantity that signifies the magnitude of the rate of change of position and also the direction of an objects movement.
Velocity
Scalar quantity that signifies only the magnitude of the rate of the rate of change of an objects movement
Speed
How far and in what direction the object is from its starting place.
Displacement
The total length of an objects travel
Distance
represented by an
arrow: the length represents the
magnitude & the head of the arrow
indicates the direction; the tail
represents the origin.
Vector
Two or more vectors can be represented by a single
vector
Resultant vector
