Transcript FUNDEMENTALS OF PHYSICS OF RADIATION SCIENCE

FUNDAMENTALS OF
PHYSICS OF RADIATION
SCIENCE
REVIEW
•
•
•
•
R or C/KG
Ion pair
defines electric charge per unit of mass
quantity of matter in a physical object is
mass
REVIEW
Rad or ?
REVIEW
Rem or ?
Curie or Becqurel (Bq)
Quantity of Radioactive material
Physics
• Removes subjectivity
• Simplifies (No… really!)
• Base quantities (mass, length and time)(pg
29)
• Derived Quantities (combination of the base
quantities
• Special quantities-support measurement of
the derived quantities
Units
• Magnitude 100 or 72
• Units
cm. or inches
SYSTEMS OF
MEASUREMENTS
• MKS
• Meter/kilogram/second
• CGS
• centimeter/gram/second
• BRITISH
• feet/pound/second
• SI
• extension of MKS +derived
units and special units to
represent derived quantities and
special quantities
MECHANICS
• OBJECTS AT REST (STATIC)
• OBJECTS IN MOTION (DYNAMIC)
• MOTION—VELOCITY AND
ACCELERATION. What is the difference?
• Initial velocity, final velocity.
• If velocity is constant the acceleration is
zero!!!
Newton’s Laws of Motion
• Inertia
• Force
• For every action there is an equal and
opposite reaction
WEIGHT
•
•
•
•
Force of an object by gravity
Newtons in SI units
Pounds in British
weight=mass x gravity
MOMENTUM
• MASS x Velocity
• Truck rolling down the hill vs skateboarder
rolling down the hill
• Which will have more momentum? Why?
WORK/POWER
•
•
•
•
PRODUCE OF FORCE AND DISTANCE
UNIT IS JOULE
Power- rate of doing work (includes time)
A radiographer picks up (force)a cassette
and places into the bucky(distance) in 3
seconds (time). This
ENERGY
• The ability to do work
• May be transformed from one form to
another but cannot be created or destroyed.
• Mechanical energies used in x-rays:
• Kinetic and potential
HEAT
•
•
•
•
•
IMPORTANT IN RADIOLOGY. WHY?
HEAT IS KINETIC ENERGY. WHY?
UNIT OF MEASUREMENT-CALORIE
CONDUCTION-HOT TOUCHING COLD
CONVECTION-TRANSFER OF
MOLECULES MECHANICALLY
• RADIATION-THERMAL
THERMAL RADIATION
• TRANSFER OF HEAT BY EMISSION OF
INFRARED RADIATION. (REDDISH
GLOW)
• X-RAY TUBES COOLED PRIMARILY
BY RADIATION