Physics and Math Chapter 4: Fluids

Question 1

What are fluids?

Answer 1

Substances that have the ability to flow and conform to the shape of their containers.

Question 2

What forces can fluids exert/notwithstand?

Answer 2

Can exert perpendicular, cannot withstand shear force.

Question 3

Which phases are considered fluid?

Answer 3

liquids and gases

Question 4

What is density?

Answer 4

Mass per unit volume of a substance

Question 5

What is pressure?

Answer 5

measure of force per unit area; it is exerted by a fluid on the walls of its container and on objects placed in the fluid

Question 6

Is pressure a scalar or vector quantity?

Answer 6

scalar - no direction; the pressure exerted by gas on the walls of its container will always be perpendicular to the container walls.

Question 7

What is absolute pressure?

Answer 7

Sum of all pressures at a certain point within a fluid. It is equal to the pressure at the surface of the fluid, usually atmospheric pressure, plus the pressure due to the fluid itself.

Question 8

What is gauge pressure?

Answer 8

name for the difference between absolute pressure and atmospheric pressure. In liquids, gauge pressure is caused by the weight of the liquid above the point of measurement.

Question 9

What is Pascal’s principle?

Answer 9

states that an applied pressure to an incompressible fluid will be distributed undiminished throughout the entire volume of the fluid.

Question 10

What are hydraulic machines?

Answer 10

operate based on the application of Pascal’s principle to generate mechanical advantage.

Question 11

What is archimede’s principle?

Answer 11

Governs bouyant force. When an object is placed in a fluid, the fluid generates a buoyant force against the object that is equal to the weight of the fluid displaced by the object.

Question 12

What determines if an object will float or sink?

Answer 12

If the maximum bouyant force is larger than the force of gravity, then it will float (if object is less dense than the fluid it is in). If the maximum buoyant force is smaller than the force of gravity on the object, then the object will sink (if the object is more dense than the fluid it is in.)

Question 13

Which way does the buoyant force face?

Answer 13

Opposite of gravity

Question 14

What is viscosity?

Answer 14

measurement of a fluid’s internal friction.

Question 15

What is viscous drag?

Answer 15

nonconservative force generated by viscosity.

Question 16

What is laminar flow?

Answer 16

Smooth and orderly, rate is determined by Poiseuille’s law.

Question 17

What is turbulent flow?

Answer 17

Rough and disorderly, causes the formation of eddies.

Question 18

What is the continuity equation?

Answer 18

statement of the conservation of mass as applied to fluid dynamics

Question 19

What is Bernoulli’s equation?

Answer 19

expression of conservation of energy for a flowing fluid. States that the sum of the static pressure and the dynamic pressure will be constant between any two points in a closed system.

Question 20

What is static pressure?

Answer 20

Associated with the height of liquid

Question 21

What is dynamic pressure?

Answer 21

Associated with the movement of liquid.

Question 22

What is the Venturi effect?

Answer 22

For horizontal flow, there is an inverse relationship between pressure and speed and in a closed system, there is a direct relationship between cross-sectional area and pressure exerted on the walls of the tube.

Question 23

What is adhesion?

Answer 23

the attractive force that a molecule of the liquid feels toward the molecules of some other substance.

Question 24

What is cohesion?

Answer 24

the attractive force that a molecule of the liquid feels toward other molecules of the same liquid

Question 25

What does the circulatory system behave as?

Answer 25

A closed system with non-constant flow

Question 26

What is arterial circulation motivated by?

Answer 26

the heart

Question 27

What is venous circulation motivated by?

Answer 27

skeletal musculature and expansion of the heart

Question 28

What does inspiration and expiration create?

Answer 28

a pressure gradient for the respiratory and circulatory system.

Question 29

What does flow rate depend on?

Answer 29

radius of the tube, pressure gradient, viscosity and length of the tube.