Introductory Concepts in Physics Flashcards
What is measurement?
The art of comparing unknown values to a standard, or the accepted set of values for a particular quantity.
What can be used to quantitatively describe physical phenomena?
Physical variables such as time, temperature and length.
When measurements are made, the units serve as…
means to compare the measured value with the standard.
In the past until the first half of the 1900s, which international organization was known to establish the different standards of the different quantities?
Metric system
Then, in 1960, the organization was called SI, which stands for?
Systéme International d’Unités (SI) or the International System of Units
Then the new name of the organization (SI) was adopted by the…
11th General Conference on the Weights and Measures
There are ___ fundamental quantities and units in the SI, these are best remembered by the acronym _____
7; METTALL
FUNDAMENTAL QUANTITIES & UNITS:
M
Physical quantity: Mass
Unit: Kilograms (kg)
Definition: an international prototype kilogram made of platinum-iridium and is kept in the International Bureau of Weights and Measures in Sévres, France
FUNDAMENTAL QUANTITIES & UNITS:
E
Physical quantity: Electric current
Unit: Ampere (A)*
Definition: the current maintained in two straight wires, placed one meter apart in vacuum which produce a force of 2 x 10^-7 Newton per meter of length
FUNDAMENTAL QUANTITIES & UNITS:
Ti
Physical quantity: Time
Unit: Second (sec)
Definition: associated with the specified transition of Cesium-133 atom, during 9 192 631 770 cycles of microwave radiation are generated by the atom
FUNDAMENTAL QUANTITIES & UNITS:
Te
Physical quantity: Temperature
Unit: Kelvin (K)
Definition: The Kelvin Scale is named after physicist William Thomson (popularly known as Lord Kelvin) and is similar in intervals in the Celsius scale. Adding 273.15 to Celsius temperature reading will equal the measure in Kelvin Scale
FUNDAMENTAL QUANTITIES & UNITS:
A
Physical quantity: Amount of substance
Unit: mole (mol)
Definition: amount of substance contained in 0.012 kg of Carbon-12. One mole of substance containes 6.02 x 10^23 particles of atom
FUNDAMENTAL QUANTITIES & UNITS:
Le
Physical quantity: Length
Unit: meter (m)
Definition: defined as the distance traveled by light in vacuum in 1/ 299 792 458 second
FUNDAMENTAL QUANTITIES & UNITS:
Lu
Physical quantity: Luminous intensity
Unit: candela (cd)
Definition: the intensity of light produced by a vacuum emitting with a frequency of 540 x 10^12 cycle/second in a direction where the intensity is 1/683 Watt per sterdian
TRUE or FALSE:
No quantities can be taken from the combination of other quantities.
FALSE because “some quantities can be taken from the combination of other quantities.”
Examples of quantities that can be taken from the combination of other quantities are….
Area, volume acceleration, force and pressure or the acronym AVAFP
Formula for AREA
Area = product of two measures of length = (l x w) = (m x m) = m^2
Formula for VOLUME
Volume = product of three measures of length = ( l x w x h) = (m x m x m) = (m^3)
Formula for ACCELERATION
Acceleration = ratio between length or distance and the square of time = m/s/s = m/s^2
Formula for FORCE
Force = product of mass and area = (kg x m/s/s) = (kg x m/s^2) = Newton
Formula for PRESSURE
Pressure = ratio between force and area = Newton/m^2 = N/m^2
Scientific notation, _______ __________ ____ __________ made during measurements.
facilitates comparisons and computations
Generally, scientific notations can be expressed as: _______,
where M is the _______ following the condition: _______
M x 10^E; mantissa; 1 ≥ M > 10 (it can be equal to one but not less than 10)
The common definition of scientific notation.
Is a way of writing very small or large numbers
Definition of measurement.
To know a specific object’s weight, height, etc. then applying appropriate units to the measured values.
scientific notation of 980 000 000 is _____.
9.8 x 10^8
scientific notation of 0.0000000000925 is _____.
9.25 x 10^-11
SCIENTIFIC NOTATION:
When the decimal moves to the right;_____,
Thus when it moves to the left;______.
negative; positive
What are significant figures?
These are any non-zero or trapped zeros.
The very basic rule for significant figures is that…
all non-zero digits are significant.
A shorthand rule for determining the significant figures of given values, is called…
Atlantic/Pacific rule, where the left part is the Pacific and the right part is the Atlantic.
Definition of accuracy
means obtaining a measurement result that is close to the theoretical or accepted value, and vise versa.
Definition of precision
denotes getting a similar result when measurement of a certain object is repeated.
What is systematic error?
this happens when the accuracy is poor and measurements are reproducible.
What is random error?
this happens when the precision is poor.
TRUE or FALSE:
Systematic errors are more problematic than Random errors.
FALSE, because random errors are more problematic since tracing the source of error is more difficult. The measurements made are not reproducible and will more likely produce a different set of measurements again.
What is least count?
A reflection of an instrument’s ability to measure minimum distance of accurately. It is the difference between the value of the main scale and the auxiliary scale divisions.
VARIABLE RELATIONSHIPS:
Direct Proportion
- as the quantity increases, the other quantity also increases proportionally.
- the graph of a direct proportion is a slanted straight line (directed to the upper right- hand corner)
VARIABLE RELATIONSHIPS:
Inverse Proportion
- as one quantity increases, the other quantity decreases proportionally.
- the graph of an inverse proportion is a parabola that approaches the lower right.
Formula for slope of line (m).
m = rise/run = change of Y/ change of X = Ysub2 - Ysub1/ Xsub2 - Ysub1
Formula for slope- intercept equation.
y = mx + b
where: y - dependent variable x - independent variable m - slope b - y-intercept (value of y when x = 0)
Formally, the general equation of the linear regression is given as…
Y = a + bx
where:
a = (∑y)(∑x^2)-(∑x)(∑xy)/ n(∑x^2)-(∑x)^2
b = n(∑xy)(∑x^2)-(∑x)(∑y)/ n(∑x^2)-(∑x)^2
