IGCSE Physics - Measurements
Best fit line graph
A graph that shows an average, a trend, or a pattern in the data
Weight
A measure of the downward force of gravity on an object because of its mass
scientific notation
A method of writing or displaying numbers in terms of a decimal number between 1 and 10 multiplied by a power of 10.
Scientific Method
A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions.
Hypothesis
A testable prediction, often implied by a theory
significant figures
All the digits that can be known precisely in a measurement, plus a last estimated digit
Volume
Amount of space occupied by an object
Parallax error
Error caused by not having your eye directly in line with the measurement
Zero error
Error due to instrument giving a small reading when it should read zero
human error
It is the biggest threat to accuracy and reliability of data.
second (s)
SI base unit for time
meter (m)
SI base unit of length
Kelvin (K)
SI base unit of temperature
Meniscus
The curved upper surface of a liquid in a tube
digital display
a display of a signal using numerical data and often precise
plumb bob
a heavy weight or mass (usually lead) that's suspended from a line that indicates vertical trueness or a vertical line
Precision
a measure of how close a series of measurements are to one another
oscillation
a repetitive motion or vibration
scientific law
a rule that describes a pattern in nature
experiment
a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact.
scientific theory
a well-tested concept that explains a wide range of observations
calibrated
agree closely with a standard or agrees when a correction has been applied
standard
an absolute or primary reference or measurements
uncertainty
an estimate of how much a measured or calculated value differs from a true value
systemic error
caused by incorrect calibration of the measuring instrument
anomaly
deviation from what is normal
Analogue display
display using mechanical pointers or needles (hands) and is often not very precise
Accuracy
how close a measurement is to the true value
period
in any periodic motion, the amount of time required for an object to repeat one complete cycle of motion
micrometer
instrument for accurately measuring small distances
vernier caliper
instrument used for measuring small and precise linear dimensions
displace
moving something to another place
Precision vs. Accuracy
precision is consistency of output whereas accuracy is alignment with the targeted value or goal
kilo (k)
prefix meaning 1000 (10^3)
mega (M)
prefix meaning 1000000 (10^6)
giga (G)
prefix that is one billion; 10^9
deci (d)
prefix; 10^-1
centi (c)
prefix; 10^-2
milli (m)
prefix; 10^-3
micro (u)
prefix; 10^-6
nano (n)
prefix; 10^-9
Tera (T)
prefix; 10^12
Units
standard quantities used to specify measurements
SI system of measurement
the International System of Units developed by scientists as a worldwide standard of measurement
kilogram (kg)
the SI unit for mass, abbreviated
Mass
the amount of matter in an object
error
the difference between the experimental value and the accepted value
Density (p)
the ratio of mass to volume for a substance mass/volume (m/V)
physics
the study of matter and energy and how they interact
immerse
to cover completely in a liquid; submerge
water displacement
used to calculate the volume of irregular shaped objects - place in water and see how much the water rises
