Physical Quantites & SI Units Flashcards
What are the 7 SI base quantities and units (MET-TALL) , also give their symbol and unit
Mass, m, Killogram (kg
Electric Current, I, ampere (A)
Time, t, second(s)
Temperature, T, Kelvin(k)
Amount of substance, n, mole (mol)
Luminous intensity, Iv, candela (cd)
Length, l, meter(m)
What are the 1 derived base units (SPEED-FAMI) PAVVV
Speed, Pressure, Energy/work, Electric charge, Density, Force, Area, Momentum, Impulse
Power, Acceleration, Velocity, Voltage and Volume
What is a homogeneous/dimensionally correct equation
An equation where the units/dimension on both sides are equal
A scalar quantity has
Magnitude only
A vector quantity has
Both magnitude and direction
Examples of scalar quantities
time speed length distance temperature mass power energy density and pressure
Examples of vector quantities
Weight, displacement, velocity, acceleration force, momentum, and electric field strength
Scientific notation
A.bc x 10 ^ d where 1 ≤ A ≤ 9
Precision is
How close a series of obtained measurements are to each other
Accuracy is
How close the obtained value is to the accepted/actual/true value
What is the precision of an instrument?
The smallest non-zero reading an instrument can measure or obtain
What is the sensitivity of an instrument?
The ability of the instrument to detect and respond to the smallest changes in the quantity being measured.
What is the range of an instrument?
The difference between the maximum and minimum value an instrument can measure
Gradient equals
The difference of the Y values over the difference of the X values
Straight line equation of a graph
y= mx + c
where m is the gradient and c is the why intercept if c=0 y and x are proportional
Logs: 4^2 =16
log Base answer power
Log 16 to the base 4= 2
F y aka vertical component =
Fsinθ
Y is sin
Fx aka horizontal component equals
Fcosθ
X is cos
θ in vectors equals
Tan-1 (Fy/Fx)
Y over X
Resultant
Square root of Fx + Fy
How do you express a physical quantity
Numerical magnitude and a unit
What is the precision of an instrument
the smallest non zero reading an instrument can obtain
what is the sensitivity of an instrument
ability to detect and respond to the smallest change in the quantity being measured
range of an instrument
the difference between the max and min value an instrument can measure
random uncertainties occur due to … which causes
the experimenter being unable to repeat his actions precisely which causes a scatter of readings about a mean value
systematic uncertainties occur due to
faulty equipment or consistently poor experimental technique
rand uncertainties have an equal chance of being
negative or positive that why we use plus or minus
Random uncertainties can be reduced by
Taking repeated measurements and finding an average value
Systematic uncertainties due to faulty equipment can be reduced and eliminated by
Recalibrating the instruments using standard instruments
Systematic uncertainties due poor experimental techniques can be reduced and eliminated by
Better experimental techniques such as eliminating parallax error by taking readings at eye level
The absolute values are added when
the quantities are added or subtracted
(Uncertainty ques.) When the quantities are multiplied or divided
the fractional uncertainties of the quantities are added
Uncertainty ques: when the quantity is raised by a power
the fractional uncertainty is of the quantity is multiplied by
the power.
constant errors in one direction are called
systematic errors
