Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

biol 325 > Properties of fluids and solids > Flashcards

Properties of fluids and solids Flashcards

1
Q

State what is resisted by solids, liquids and gas

A

solids: resist compression, shear and tension
liquids: resist compression and tension
gas: resist compression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is compression

A

inward force is applied to the material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is tension

A

outward force is applied to the material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do we classify solids

A
  1. composition
    - simple: made of 1 material
    - compound: made of 2 material
  2. directional dependence
    - ansiotropy: mechanical properties are directionally dependent
    - isotropy: mechanical properties are not directionally dependent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is tensile, pliant and rigid

A

tensile: capable of being stretched
pliant: capable of being bent
rigid: can’t be forced out of shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a Hookean material

A

displacement is directly proportional to the applied load ( ie. force/ dx)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does a force vs displacment graph tell us

A

tells us the elasticity of the material, gives hooke’s constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do we normalize a force vs displacement graph

A

divide the force by cross sectional area (gives stress) and divide the change in length by total length (gives strain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is strength in a stress-strain curve

A

It is the stress recorded at failure point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is extensibility in a stress-strain curve

A

It is the max. strain recorded at failure point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is elasticity in a stress-strain curve

A

It is the slope measured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is resilience in a stress-strain curve

A

It is the ratio of work done during contraction/ work done during extensibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is toughness in a stress-strain curve

A

It is the work done (area under the curve) till failure point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why are biological materials expressed in a J shaped stress strain curve

A

materials such as collagen are extensible and so are initally elastic until they are taunt and cannot be stretched much longer ( resulting in steep increase in elasticity –becomes stiff) where there is permanent deformation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Should spider silk have high or low resilience

A

should have low resilience because you don’t want a lot of the energy to be conserved you don’t want the silk to conserve the energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Draw a graph of low resilience

A

stress strain area under w.d due to contraction should be a lot lower than w.d due to extension

17
Q

What is shear stress

A

It is a force applied perpendicular to the SA

18
Q

What is shear strain

A

the amount moved in x direction / height

19
Q

What is the shear modulus

A

shear stress/ shear strain

20
Q

What is the ideal gas law

A

PV =nRT

21
Q

What is Boyle’s law

A

under constant temp PV= constant

22
Q

What happens when a shear stress is applied to a fluid

A

fluid flows

23
Q

What is the difference between a fluid and solid upon shear stress application

A

fluid flows, solid deforms in shape

24
Q

How do we increase the velocity of a fluid being sheared

A

increase the shearing force

25
Q

What is dynamic viscosity

A

shear stress/ shear strain RATE= viscosity. it is the slope of shear stress vs shear strain RATE curve

26
Q

Calculate the viscosity for a fluid in a 1mm depth container where 100 Pa of shear stress is applied, where the boundary layer is flowing at 5mm/s

A

100/ (5mm/s /1mm) = 20 Pa s

27
Q

What is a shear strain rate

A

It is the velocity gradient ( in terms of depth of the container) It is the change in velocity / the change in distance

28
Q

Describe how Netwonian fluids relate in a shear stress and shear strain rate curve

A

Newtonian fluid have a constant viscosity so their slope from shear stress to shear strain rate is constant

29
Q

What are the other non-Netwonian like fluids ( draw their curves on a shear stress vs shear strain rate graph)

A
  1. shear thinning fluid: as shear stress increases become less viscous
  2. shear thickening fluid: more shear stress fluid becomes more viscous
  3. Bingham plastics: After a certain shear stress is applied, object has viscosity
30
Q

What is a shear thinning fluid

A

blood,

31
Q

What is a viscoelastic material

A

has viscosity and elasticity

32
Q

Draw the stress strain curve for elastic material

A

slide 24 L 7

33
Q

Draw the stress strain curve for viscous material

A

slide 25 L 7

34
Q

Draw the stress strain curve for viscoelastics materials

A

slide 26 L 7

35
Q

What objects have stress and strain in phase

A

elastic material

36
Q

what objects have stress and strain 90 degrees out of phase

A

viscous materials

37
Q

Name a shear thickening fluid

A

synovial fluid

biol 325 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions