physics fluids & gases

Question 1

The absolute temperature of any system is directly proportional to the _____________________

the absolute temperature scale is used to quanity the temperature of objects relative to _____________

Answer 1

• to the average kinetuc energy of the molecules within the system
  
  • Therefore, the temperature of gas molecules moving throughout an enclosed container is determined not by the kinetic energy of any one gas molecule but rather by the average kinetic energy of all gas molecules.
• the absolute temperature scale quantifies relative to absolute zero
  
  • ​it is the temperature at which matter achieves the lowest possible total energy of matter (KE + PE)
  • “absolute” bc it is the same for all matter, regardless of atomic structure or molecular configuration

Question 2

Characteristics of an ideal gas

Answer 2

Question 3

Deviations from ideal gas behavior

Answer 3

Question 4

Bernouli’s equation & the Venturi effect

Answer 4

• The Venturi effect describes the decrease in pressure observed concurrent to an increase in fluid velocity.
• The Venturi effect is modeled by Bernoulli’s equation, which describes the conservation of energy in fluids.

Question 6

Continuity of flow in a non-uniform conduit

Answer 6

Question 7

Circulation/biological mechanisms of enviromental heat transfer

what can increase the rate at which mammals lose body heat the the enviroment?

Answer 7

• Heat transfer from an organism to the environment can be accomplished by increasing superficial blood flow (enhancing thermal conduction) or by increasing respiration (enhancing conduction and convection).
• heat transfer between two objects or regions occurs until temperature equalizes
• Heat transfer to the environment through ventilation occurs through a similar mechanism except that conductive heat transfer to inhaled air is followed by convective heat transfer through exhalation. Therefore, increasing the rate of respiration increases the rate of heat loss to the environment.
• (replacing ambeint air with warmer air would dec rate of heat loss to the enviroment)
• 1. conduction: direct/physical contact*
• 2. convection: molecules with high KE (temp) move to domain where molecules have lower kinetic energy*

Question 8

Heat transfer between objects connected by thermal conductor

Answer 8

Question 9

Vasoconstriction & vasodilation

which decreases & increases the rate of conductive heat loss to the enviroment?

Answer 9

vasoconstriction decreases the rate of conductive heat loss to the environment and vasodilation increases it

Question 10

Inspiration

Answer 10

Question 11

Archimedes’ principle

Answer 11

Question 12

Pulmonary resiliency

Answer 12

• Pulmonary resiliency (elastic recoil and surface tension effects) refers to the tendency of the lungs to return to their original shape after being stretched during inhalation (they decrease alveolar volume)
• Pulmonary resiliency allows for passive expiration and does not require muscles or ATP energy, and can therefore occur under the paralytic effects of anesthesia.

Question 13

Elastic Recoil

Surfance Tension

Answer 13

• Elastic recoil refers to the elasticity of elastin fibers making up alveolar tissues. These fibers are crosslinked and are capable of being stretched like a spring. When stretched, these fibers exert a restorative force on the lungs following inspiration.
• Surface tension: refers to the tendency of a liquid to reduce exposed surface area due to attractive intermolecular forces between its molecules.
  
  • Surface tension is signficant at alveolar surfaces due to hydrogen bonds between water molecules lining the alveolar sacs. Because surface area increases when the alveoli expand, surface tension exerts a collapsing pressure on the alveoli.

Question 14

Venturi Effect

Answer 14

• refers to the reduction of fluid pressure that occurs when flow velocity increases at constricted sections of a tube.

Question 15

Turbulent Flow & lungs

Answer 15

• refers to a disorganized type of fluid that occurs at high velocities
• turbulent flow increases flow resistance, which impede exhalation

Question 16

Surface tension in depth

Answer 16

• surface tension of a liquid is result of strong cohesive forces between its molecules
• surface tension creates a tendency to decrease surface area due to a net inward force at the surface molecules
• water has high surface tention due to its ability to form hydrogen bonds

Question 17

Explain the capillary action phenomenon of a liquid:

Answer 17

• refers to the phenomenon of a liquid “climbing up” a thin glass tube due to relatively high adhesive forces (water to glass) compared to cohesive forces (water to water)
• Water with high surface tention would not travel farther in a thin glass tube because water is more atrrated to itself than to the glass surface

Question 18

When does evaporation occur?

Answer 18

• Evaporation occurs when the kinetic energy of a molecule can overcome intermolecular forces at the surface of the liquid.
• Fewer evaporative events would occur because more energy would be required to break the greater cohesive forces of high surface tension water.

Question 19

Van del Waals forces & water

Answer 19

• Van der Waals forces are attractive forces between molecules that do not arise from covalent or ionic bonds.
• Common examples include dipole-dipole forces and hydrogen bonds.
  
  • Therefore, water with greater surface tension will have stronger van der Waals forces.

Question 20

Magnification in convex lenses

Answer 20