Physical Quantities and SI units Flashcards
What is a Physical quantity?
The physical quantity is the arithmetical product of a numerical value and a unit:
Physical quantity = numerical value · unit.
It is characterized by a letter for example m=mass.
What is a Scalar?
A physical quantity that has a magnitude describable by a real number and NO DIRECTION . e.g., body temperature. The expression T = 37 °C fully describes the quantity.
What is a Vector?
A physical quantity with spatial direction, e.g. the speed of an aircraft. To fully describe the quantity it is not enough to give the magnitude and unit of speed (e.g. 900 km/h), but the DIRECTION of movement must also be provided.
SI Base Units
What is the SI Unit for Time? Symbol?
Time - Seconds - s
SI Base Units
What is the SI Unit for Length? Symbol?
Length - Meters - m
SI Base Units
What is the SI Unit for Mass? Symbol?
Mass - Kilograms - kg
SI Base Units
What is the SI Unit for Electric current? Symbol?
Electric current - Ampere - A
SI Base Units
What is the SI Unit for Temperature? Symbol?
Temperature - Kelvin - K
SI Base Units
What is the SI Unit for Amount of Substance? Symbol?
Amount of Substance - mole - mol
SI Base Units
What is the SI Unit for Unit of Luminous Intensity?Symbol?
Luminous Intensity - candela - cd
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^15? Symbol?
peta = 10^15, Symbol is P
e.g. 2 petameter = 2 x 10^15 meter = 2 Pm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^12? Symbol?
tera = 10^12, Symbol is T
e.g. 2 terameter = 2 x 10^12 meter = 2 Tm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^9? Symbol?
giga= 10^9, Symbol is G
e.g. 2 gigameter = 2 x 10^9 meter = 2 Gm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^6?Symbol?
mega= 10^6, Symbol is M
e.g. 2 megameter = 2 x 10^6 meter = 2 Mm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^3? Symbol?
kilo= 10^3, Symbol is k
e.g. 2 kilometer = 2 x 10^3 meter = 2 km
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^2? Symbol?
hecto= 10^2, Symbol is h
e.g. 2 hectometer = 2 x 10^2 meter = 2 hm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^1? Symbol?
deca= 10^1, Symbol is da
e.g. 2 decameter = 2 x 10^1 meter = 2 dam
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^-1? Symbol?
dec= 10^-1, Symbol is d
e.g. 2 decimeter = 2 x 10^-1 meter = 2 dm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^-2? Symbol?
centi= 10^-2, Symbol is c
e.g. 2 centimeter = 2 x 10^-2 meter = 2 cm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^-3? Symbol?
milli= 10^-3, Symbol is m
e.g. 2 millimeter = 2 x 10^-3 meter = 2 mm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^-6? Symbol?
micro= 10^-6, Symbol is μ
e.g. 2 micrometer = 2 x 10^-6 meter = 2 μm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^-9? Symbol?
nano= 10^-9, Symbol is n
e.g. 2 nanometer = 2 x 10^-9 meter = 2 nm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^-12? Symbol?
pico= 10^-12, Symbol is p
e.g. 2 picometer = 2 x 10^-12 meter = 2 pm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^-15? Symbol?
femto= 10^-15, Symbol is f
e.g. 2 femtometer = 2 x 10^-15 meter = 2 fm
Prefixes for the International System of Units (SI) Powers of ten Prefix for 10^-18? Symbol?
atto= 10^-18, Symbol is a
e.g. 2 attometer = 2 x 10^-18 meter = 2 am
Distance (m) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Distance (m) is a Scalar
Magnitude without Direction
e.g. The distance between the moon and the earth
Displacement (m) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Displacement (m) is a Vector
Magnitude with a Direction
e.g. The displacement path of someone on earth to the moon.
Speed (m/s) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Speed (m/s) is a Scalar
Magnitude without Direction
e.g. the speed of a box on a moving straight assembly line
Velocity (m/s) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Velocity (m/s) is a Vector
Magnitude with a Direction
e.g. the velocity of a rat running perpendicular to the moving assembly line
Time (s) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Time (s) is a Scalar
Magnitude without Direction
e.g. the time necessary to boil an egg in room temperature
Mass (kg) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Mass (kg) is a Scalar
Magnitude without Direction
e.g. the mass of an egg
Weight (N) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Weight (N) is a Vector
Magnitude with a Direction
e.g. the weight of a egg pressing against you as you try to lift it up.
Acceleration (m/s^2) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Acceleration (m/s^2) is a Vector
Magnitude with a Direction
e.g. The deceleration of your car as you hit the brake to reach a full stop (*against the vector of you velocity).
Temperature (K)- Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Temperature (K) is a Scalar
Magnitude without Direction
e.g. the temperature of a boiled egg
Pressure (Pa)- Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Pressure (Pa) is a Scalar
Magnitude without Direction
e.g. the pressure at the depth of 20 meters below sea level
Force (N)- Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Force (N) is a Vector
Magnitude with a Direction
e.g. The Force that you apply against an egg’s weight in order to lift it up.
Work (J) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Work (J) is a Scalar
Magnitude without Direction
e.g. the Work done by you lifting an egg from the table to the pot or the work done by you lifting an egg from the pot to the table
Power (J/s) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Power (J/s) is a Scalar
Magnitude without Direction
e.g. the Work done by you lifting an egg from the table to the pot PER SECOND
Moment (N*m) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Moment (N*m) is a Vector
Magnitude with a Direction
e.g. The Moment of an egg as it hits the wall when you throw it in a specific angle and force
Energy (J) - Scalar or Vector?
** This term will be fully explained as we move to the next sections of the course
Energy (J) is a Scalar
Magnitude without Direction
e.g. the Energy needed (Heat) in order to boil an egg
Greek Alphabet - Used in Sciences
What is this letter - α ?
What is the use of this letter in Physics?
α - Alpha
It is used to denote Multiple Quantities: Angle, Alpha type of Radiation and Angular Acceleration.
Greek Alphabet - Used in Sciences
What is this letter - β ?
What is the use of this letter in Physics?
β- Beta
It is used to denote Multiple Quantities: Angle and Beta type of Radiation.
Greek Alphabet - Used in Sciences
What is this letter - γ ?
What is the use of this letter in Physics?
γ - Gamma
It is used to denote Multiple Quantities: Gamma type of Radiation and therefore it is also the symbol for a Photon.
Greek Alphabet - Used in Sciences
What is this letter - δ?
What is the use of this letter in Physics?
δ - Delta
It is used to denote Multiple Quantities of them Angle is the one relevant for us.
Greek Alphabet - Used in Sciences
What is this letter - Δ?
What is the use of this letter in Physics?
Δ - Uppercase Delta
It is used to denote a CHANGE in a physical quantity.
For example, the change of Time is denoted as Δt.
Greek Alphabet - Used in Sciences
What is this letter - ε?
What is the use of this letter in Physics?
ε - Epsilon
It is used to denote the Dielectric Constant of a Substance or Relative permittivity.
Greek Alphabet - Used in Sciences
What is this letter - θ?
What is the use of this letter in Physics?
θ - Theta
It is used to denote Multiple Quantities of them Angle is the one relevant for us.
Greek Alphabet - Used in Sciences
What is this letter - κ?
What is the use of this letter in Physics?
κ - Kappa
It is used to denote Multiple Quantities of them Diffusion Constant is the one relevant for us.
Greek Alphabet - Used in Sciences
What is this letter - λ?
What is the use of this letter in Physics?
λ - Lambda
It is used to denote Multiple Quantities: Wave Length, Volume and Radioactive Decay.
Greek Alphabet - Used in Sciences
What is this letter - μ?
What is the use of this letter in Physics?
μ - Miu
It is used to denote Multiple Quantities: Micro- (10^-6) and Friction Constant.
Greek Alphabet - Used in Sciences
What is this letter - π?
What is the use of this letter in Physics?
π - Pi
It is used to denote the Constant Geometric Ratio between the Circumference of a circle to its Diameter.
π = 3.1416 (Always).
Greek Alphabet - Used in Sciences
What is this letter - ρ?
What is the use of this letter in Physics?
ρ - Rho
It is used to denote Multiple Quantities: Density, Charge Density and Specific Electrical Resistance.
Greek Alphabet - Used in Sciences
What is this letter - Σ?
What is the use of this letter in Physics?
Σ - Uppercase Sigma
It is used to denote SUMMATION in Mathematics and Physics. ΣF = F1 + F2 + F3.
Greek Alphabet - Used in Sciences
What is this letter - σ?
What is the use of this letter in Physics?
σ - Sigma
It is used to denote Charge Density over Area.
Greek Alphabet - Used in Sciences
What is this letter - ω?
What is the use of this letter in Physics?
ω - Omega
It is used to denote Angular Frequency and Angular Velocity.
Greek Alphabet - Used in Sciences
What is this letter - Ω?
What is the use of this letter in Physics?
Ω - Uppercase Omega
It is used to denote the Unit Ohm for Electrical Resistance.
Greek Alphabet - Used in Sciences
What is this letter - ψ?
What is the use of this letter in Physics?
ψ - Psi
It is used to denote the Electric Flux.
Greek Alphabet - Used in Sciences
What is this letter - Φ?
Φ - Phi
It is used to denote the Electric Potential.
Greek Alphabet - Used in Sciences
What is this letter - τ?
What is the use of this letter in Physics?
τ - Tau
It is used to denote the Time of Charging in RC Circuits.
Greek Alphabet - Used in Sciences
What is this letter - ν?
What is the use of this letter in Physics?
ν - Nu
It is used to denote the Frequency (as alternative for f).
What are the Base Quantities ?
Chosen quantities, all other quantities are originated from them. These are : Time, Length, Mass, Electric Current, Temperature, Amount of Substance and Luminous Intensity.
What are Derived quantities and their units?
Derived quantities and their units are defined by using the base quantities and base units.They are usually defined by a formula.
Give an example for a derived quantity and it’s unit using Length with Time. Add the Formula.
Velocity (𝑣) is defined as the distance (or length) travelled (Δx) in an interval of time (Δ𝑡) divided by the duration of that interval (𝑣 = Δx/Δ𝑡). It’s unit is[m/s^2] .
** You will get more familiar with the Derived quantities and units as we advance in our Biophysics course.
Give an example for a derived quantity and it’s unit using 2 different Lengths (2 Dimensional Value). Add the Formula.
Area (A) is defined as the length (x1) of an interval times another length (x2) of an interval (A = x1*x2). It’s unit is [m^2] .
** You will get more familiar with the Derived quantities and units as we advance in our Biophysics course.
Give an example for a derived quantity and it’s unit using 3 different Lengths (3 Dimensional Value). Add the Formula.
Volume (V) is defined as the length (x1) of an interval times another length (x2) of an interval and times another length (x3) of an interval (A = x1x2x3). It’s unit is [m^3] .
** You will get more familiar with the Derived quantities and units as we advance in our Biophysics course.
