CHAPTER 2 Flashcards
(26 cards)
The study of interactions of matter & energy
Physics
Mass, Length & Time
Three Base Quantities
The combination of one or more base
quantities
Secondary/Derived Quantities
Exposure, Dose, Equivalent Dose &
Radioactivity
Special Quantities
IBWM
International Bureau of Weights &
Measures
It is based on speed of light
SI Unit: meter (m)
Length
represents the
standard unit of length
Platinum-Iridium Bar:
wavelength of orange light
emitted from an isotope of krypton-86
Redefinition:
distance traveled by light in
1/299,792,468
One Meter:
One Kilogram:mass of 1000 cm3 of water at
4 DEGREES CELCIUS
SI Unit: kilogram (kg)
SI Unit: kilogram (kg)
MASS
represents the
standard unit of mass
MASS
Redefinition: a certain fraction of the
tropical year 1900
MASS
Recent Definition: measured by an atomic
clock
MASS
It has a magnitude & a unit
Measurement
Four Systems of Units
MKS
CGS
British
SI
Exposure: SPECIAL UNITS ___ SI ___
C/kg
Air kerma (Gya)
Dose: SPECIAL UNITS ___ SI ___
J/kg
Gray (Gyt)
Equivalent Dose:SPECIAL UNITS ___ SI ___
J/kg
Sievert (Sv)
Radioactivity:SPECIAL UNITS ___ SI ___
s
-1 Becquerel (Bq)
The segment of physics that deals with
motion at rest (statics) & objects in motion
(dynamics)
Mechanics
motion at rest
statics
objects in motion
dynamics
It is sometimes called speed
The rate of change of its position with time
Velocity
