Chapter 15 - Fluids

Question 1

what are the intermolecular bonds like in solids

Answer 1

strong

Question 2

what are the intermolecular bonds like in liquids

Answer 2

weak

Question 3

what are the intermolecular bonds like in gases

Answer 3

negligible

Question 4

what does the average direction of the force on a surface = and why

Answer 4

the force perpendicular to the surface because the tangential components tend to cancel out

Question 5

is pressure scalar or vector

Answer 5

scalar

Question 6

is force scalar or vector

Answer 6

vector

Question 7

what is pascals law

Answer 7

any additional pressure applied to an enclosed fluid is transmitted undiminished to all parts of the fluid and the enclosing walls

Question 8

does pressure in a uniform static fluid depend on height

Answer 8

yes

Question 9

does pressure in a uniform static fluid depend on shape of vessel

Answer 9

no

Question 10

where is pressure constant

Answer 10

for all points along a horizontal surface on or in the fluid

Question 11

how many atm in 10m of water

Answer 11

1atm

Question 12

how many atm in 100m of water

Answer 12

10atm

Question 13

how many atm in 1m of water

Answer 13

0.1atm

Question 14

what do gauge pressures measure

Answer 14

the difference between ambient atmospheric pressure and the unknown pressure
(Ptot-Po)

Question 15

which direction does the buoyant form point

Answer 15

upwards against gravity

Question 16

what is Archimedes principle

Answer 16

magnitude of buoyant force = weight of fluid displaced by object

Question 17

what are 3 key points of Archimedes principle

Answer 17

1-true for object of any shape
2-true for fully or partially submerged objects
3-true for objects simultaneously immersed in more than one fluid

Question 18

what are our 3 assumptions that we made in fluid dynamics

Answer 18

1- ideal fluid
2-laminar flow
3-steady state flow

Question 19

what is an ideal fluid

Answer 19

non-viscous and non-compressible

Question 20

what is laminar flow

Answer 20

no turbulence

Question 21

what is steady-state flow

Answer 21

flow characteristics are constant over time (speed, pressure…)

Question 22

what does the continuity equation say

Answer 22

that, for a steady-state flow of an ideal fluid, the volume flow rate is constant throughout the flow system

Question 23

what is constant in the continuity equation

Answer 23

the volume flow rate

Question 24

what does an increase in fluid speed get accompanied by

Answer 24

drop in pressure

Question 25

what is a counterintuitive thing that happens in the Bernoulli effect

Answer 25

an increase in fluid speed gets accompanied by a drop in pressure

Question 26

what are 2 main assumptions with the Bernoulli effect

Answer 26

1-when fluid is open to air, P=Po

2-when flowing from a large pipe to a small one, if A1<

Question 27

what is viscosity

Answer 27

measure of resistance to flow

Question 28

what causes viscosity (2)

Answer 28

friction between flowing fluid and container wall and friction between adjacent fluid layers

Question 29

what must you assume in the Bernoulli equation

Answer 29

that there is zero viscocity

Question 30

which law do we use if the viscosity is specified

Answer 30

Poiseuille

Question 31

which 2 things are we going to assume are always true

Answer 31

steady-state and continuity equation