Fluids

Question 1

Weight of a volume = ?

Answer 1

Fg = density . V . g

Question 2

Specific gravity = ?

Answer 2

SG = density / 1 g/cm^3

Question 3

Pressure = ?

Answer 3

F (normal force)/A

Question 4

760 mmHg = ? Pa

Answer 4

1 . 10^5 Pa

Question 5

760 mmHg = ? atm

Answer 5

1 atm

Question 6

Net force on an object with pressure differentials on each side (like a window) = ?

Answer 6

Fnet = (Poutside - P inside) . A

Question 7

Absolute (hydrostatic) pressure =?

Answer 7

P = Po (at the surface) + density(fluid).g.z (depth)

Question 8

Gauge pressure = ?

Answer 8

P gauge = P - P atm

Question 9

What are the 3 equations for Pascal’s principle and what does it apply to?

Answer 9

P = F1/A1 = F2/A2
V = A1d1 = A2d2
W=F1d1=F2d2
Applied to hydraulic systems

Question 10

What is the buoyant force equal to?

Answer 10

Fbuo = density of fluid . Volume of fluid displaced . g = density of fluid . Volume of fluid submerged . g

Question 11

How can you tell if an object is floating based on its density?

Answer 11

If its average density

Question 12

Poiseuille’s law = ?

Answer 12

Q = pi . r^4 . Delta P / 8. viscosity. L

Question 13

Critical speed of a fluid = ?

Answer 13

Vc = Nr (Reynolds number) . viscosity / density. D (diameter)

Question 14

Continuity equation = ?

Answer 14

Q = v1.A1 = v2.A2

Question 15

Bernouilli’s equation = ?

Answer 15

P1 + 1/2.density.v1^2 + density.g.h1 = same with 2s

Question 16

When 1 liquid rests on the other, what is Patm in the gauge pressure equation of the liquid on the bottom?

Answer 16

P atm = Patm + gauge P of liquid on top

Question 17

Is the speed of the blood faster in the aorta or the capillaries? Why?

Answer 17

Blood in aortas is faster than in capillaries, because the sum of all cross-sectional areas of capillaries is larger than the cross-sectional area of aorta.

Question 18

Which equation in this chapter is applicable to human circulation?

Answer 18

Poiseuille’s Law

Question 19

What is the effect on pressure of decreasing a fluid’s speed?

Answer 19

Increase the pressure!

Question 20

What is necessary for a fluid to flow out of something? What is an example?

Answer 20

Its pressure needs to exceed to pressure of the system it is going into → in order to breath out, pressure in the alveoli needs to be higher than atmospheric pressure

Question 21

What is a super critical fluid?

Answer 21

Any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist. It can effuse through solids like a gas, and dissolve materials like a liquid.