1. Basic Physics for the Respiratory Therapist
Chapter 1
Basic Physics for the Respiratory Therapist
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2. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Lecture Outline
Energy and matter
States of matter
Physical properties of liquids and gases
Gas laws
Fluid mechanics
Principles of electricity
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Energy and Matter
Energy and work
W = F x d
Energy is the ability to do work
Types of energy
Mechanical
Thermal
Chemical
Sound
Nuclear
Electrical
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

4. Energy and Matter (Cont.)
Law of conservation of energy
Energy cannot be created or destroyed, only transferred
Work = transfer of energy by mechanical means
Mechanical energy
Kinetic energy
Potential energy
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

5. Energy and Matter (Cont.)
Kinetic energy = ½ (mv2)
Examples
Breaking of chemical bonds
Hitting a ball
Burning of fuel
Water over a falls
Potential energy = mgh (mass, force of gravity, height of the object)
Examples
Coiled spring
Stretched rubber band
Bicycle at top of hill
Ice before it melts
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6. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Physics
Branch of science that deals with interaction of matter and energy
Fields that make up physics:
Mechanics
Optics
Acoustics
Electricity
Magnetism
Thermodynamics
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7. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Energy and Work
Work is product of force and distance
Energy and work are expressed in joules
One joule is force required to move 1 kilogram 1 meter
Power measures rate at work being performed
Watts is unit of measure for power
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Types of Energy
Kinetic energy – associated with movement
Potential energy – amount of energy an object has due to its position
When coal is burned, its potential energy is released
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9. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
States of Matter
Matter – anything that has mass and occupies space
Composed of atoms
Atoms – molecules – compounds/mixtures
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10. States of Matter (Cont.)
Points: Solid has the most potential energy and the least kinetic energy; strong bonds; limited motion of molecules.
Liquids have more kinetic energy than solids; cohesive bonds not as strong as with solids.
Gases have the least potential energy and the most kinetic energy; have extremely weak bonds
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11. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Temperature
The measure of average kinetic energy of molecules in an object
Thermometers are used to measure temperature
Types of thermometers
Nonelectrical
Electrical
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12. Temperature Conversions
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13. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Formulas
°C = 5/9 (°F – 32)
°F = (9/5 x °C) + 32
K = °C + 273
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14. Practice Temperature Conversions
1. 25°C = ?°F 2. 35°C = ?°F 3. 37°C = ?°F 4. 39°C = ?°F 5. 39°C = ? k
6. 70°F = ?°C 7. 78°F = ?°C 8. 90°F = ?°C °F = ?°C °F = ? k
Answers:
1. 77°F °C
2. 95°F °C
°F °C
°F °C
k k
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15. Pressure Conversion: Units
cm H2O
mm Hg
psi (lb/in2)
atm
kPa
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16. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Pressure Conversions
cm H2O x = mm Hg
cm H2O x = kPa
mm Hg  = atm
atm x = psi
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

17. Practice Pressure Conversions
1. 25 cm H2O = ? mm Hg cm H2O = ? mm Hg mm Hg = ? cm H2O mm Hg = ? cm H2O mm Hg = ? kPa 6. 2 atm = ? mm Hg psi = ? atm
Answers:
18.39 mm Hg
22.06 mm Hg
cm H2O
cm H2O
kPa
1520 mm Hg
atm
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18. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
The Gas Laws
Boyle’s Law
Charles’s Law
Gay-Lussac’s Law
Combined Gas Law
Dalton’s Law of Partial Pressure
Avogadro’s Law
Graham’s Law
Henry’s Law
Fick’s Law of Diffusion
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19. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Thank you
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.