Brainscape's Knowledge GenomeTM

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


See full index

AS levels Resurrection > P 5. Solids under stress Revamp > Flashcards

P 5. Solids under stress Revamp Flashcards

1
Q

Almost there

A

u right

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

Experiment to learn?

A

When the case calls

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

Define limit of proportionality

A
  • When the proportional behaviour
  • of forces and extension stops
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define elastic limit

A
  • Point at which deformation
  • ceases to be elastic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define permanent extension

A

When it’s permanent, irreversible deformation

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

Define elastic behaviour

A
  • When extension disappears when force is removed
  • returns to its original size and shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define plastic behaviour

A
  • When extension decreases
  • only slightly when stress is removed
  • Doesn’t return to its original size and shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define Hooke’s law?
(4-way)

A
  • The tension in a spring or ware
  • is proportional to its extension
  • from its natural length
  • within the limit of proportionality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hooke’s law formula?

A

F = kx

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

Define F
(Hooke’s law)

A

Force applied/tension
(N)

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

Define k
(Hooke’s law)

A

The spring constant
(force per unit extension)

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

Define x
(Hooke’s law)

A

The extension from the spring’s natural length
(mm, cm, m)

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

What do springs look like in parallel?

A

1 hanging each side

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

What do springs look like in series?

A

Hanging on top of each other

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

If springs are in parallel, what happens to the k?
(2-way… + 1 thing)

A
  • x = doubled
  • k = halved
  • k1 + k2 = ktotal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

If springs are in series, what happens to the k?
(2-way… + 1 thing)

A
  • x = halved
  • k = doubled
  • 1/k1 + 1/k2 = 1/ktotal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is the energy stored in stretched spring equation formed?

A
  1. Area under line on force-distance graph = wd
  2. Likewise to Hooke’s law thing
  3. E = ½ Fx
  4. Sub in F = kx
  5. E = ½ kx2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Therefore, what’s the equation to find energy stored in a stretched spring?
(in data booklet)

A

E = ½ kx2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Define stress

A

Force per unit cross-sectional area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Formula for tensile stress (σ)?

A

σ = N/m2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Formula for tensile stress expressed in words?

A

Tensile stress = Force/Area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Define σ
(Tensile stress formula)

A

Tensile stress…
(Nm-2 or Pa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Define N
(Tensile stress formula)

A

Force
(Newtons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Define m2
(Tensile stress formula)

A

Area
(x2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Define strain

A

Extension per unit length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Formula for tensile strain (ε)?

A

ε = m/m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Formula for tensile strain expressed in words?

A

Tensile strain = extension/length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Define ε
(Tensile strain formula)

A

… tensile strain
(A ratio, no units)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Define the m’s
(Tensile strain formula)
(2-way)

A
  • Extension above
  • Length below
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

For any material, if we work within the limit of proportionality, what happens to the ratio for stress/strain?
What’s it called?

A
  • Becomes a constant value
  • YOUNG MODULUS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Formula for young modulus (E)?

A

E = σ/ε

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What’s an easier equation for young modulus?

A

E = Fl/Ax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How is the easy young modulus equation developed?
(3 steps)

A
  1. E = (F/A)/(x/l)
  2. = F/A x l/x
  3. = Fl/Ax
34
Q

Define elastic?
(2-way)

A
  • Material that regains its shape
  • after stresses are removed
35
Q

Define ductile?
(2-way)

A
  • Material that can be easily stretched
  • or drawn into a wire
36
Q

Define malleable?
(2-way)

A
  • Material able to be hammered or pressed
  • into a shape without breaking/cracking
37
Q

Define brittle?
(2-way + e.g.)

A
  • Material that’ll snap
  • without yield
  • … without any give
38
Q

Define stiff?
(1-1-way)

A
  • Small strains for large stresses
  • ;Not stretch or bendy
39
Q

Define plastic?
(2-way)

A
  • Material that undergoes permanent deformation
  • under large stress rather than cracking
40
Q

Define strong?
(in terms of this topic)

A

Large stress needed to break it

41
Q

Define hard?
(in terms of this topic)

A

Resists indentation on impact

42
Q

Topics left…?

A
  • Stress-strain graph for ductile metals
  • Brittle material
  • Polymeric materials
    Finish in time o7…. it seems we have an alternate path
43
Q

What are the 3 categories used to classify solid materials?

A
  • Crystalline solids
  • Amorphous solids
  • Polymeric solids
44
Q

What type of materials are crystalline solids?
(psh remember 1/4)

A
  • Metals
  • Diamond
  • Graphite
  • Salt
45
Q

Define crystalline solids
(2 things)

A
  • Atoms arranged into a crystal lattice
  • Consists of regularly repeating unit cells
46
Q

What do crystalline solids exhibit?

A

Long-range order and symmetry

47
Q

What’s the jig with poly-crystalline structures?
(3 things)

A
  • Structure split up into many small crystallites/grains
  • Randomly arranged
  • Forms different grain boundaries
48
Q

What type of materials are amorphous solids?
(remember 1/3)

A
  • Glass
  • Ice
  • Ceramics
49
Q

Define amorphous solids?
(2-way + 2-way)

A
  • Atoms have no long-range order
  • … Or symmetry
  • Considered to be super cooled liquids:
  • atoms randomly arranged, no overall pattern
50
Q

What do amorphous solids tend to be more?
(2-way)

A
  • Brittle
  • with little elasticity
51
Q

What type of materials are polymeric solids?
(remember 1/4)

A
  • Rubber
  • Cellulose
  • Polyethylene (ploythene)
  • PVC
52
Q

Define polymeric solids?
(1 thing + 3-way)

A
  • Compromised of long molecular chains
  • Consists of basic units:
  • monomers repeatedly linked together
  • w/ strong covalent bonds
53
Q

If the polymeric solid is randomly tangled up, what can be said bout’ it?
(2 things)

A
  • Amorphous
  • No long-range order
54
Q

How can a polymeric solid display semi-crystalline properties?

A
  • Stretched rubber
  • When chains are untangled
55
Q

Crystalline solid in molecular terms?
(2-way)

A
  • Long range order
  • Lattice arrangement
56
Q

Amorphous solid in molecular terms?
(2-way)

A
  • Short/no range order
  • Random arrangement
57
Q

Polymeric solid in molecular terms?

A

Long chain molecule arrangement

58
Q

Define elastic strain
(1 thing, 2-way + 2 features)

A
  • Force applied to a material
  • Atoms stretched apart
  • … by a very small distance
  • Strain measures = relatively small forces
  • Small strains = no bonds broken
59
Q

Define plastic strain
(2-way-aparts + 1 main)

A
  • Imperfections within a lattice:
  • Edge dislocations
  • … causing bonds to break
60
Q

Explain the theory suggesting lattices contain imperfections
(1 thing + 2-way)

A
  • Mistakes within structure
  • Incomplete plane of atoms creating
  • “an edge dislocation”
61
Q

What are edge dislocations?
(2-way + 2-way)

A
  • Creates a point of weakness within material…
  • where large stresses occur
  • These points = material start to fail if…..
  • Larger forces applied here
62
Q

Movement of edge dislocation = ?

A

Plastic deformation

63
Q

What’s the symbol representing edge dislocation?

A

⊥
(wowow)

64
Q

How the edge dislocation move within a material?
(2-way + 2-way)

A
  • If shear stress applied
  • dislocation migrates throughout material
  • New bonds made to the left….
  • edge dislocation moves to the right
65
Q

What causes permanent deformation within material?
(2-way + 2-way + 1 thing)

A
  • Not applying force….
  • to move the dislocation
  • Plastic strain occurred
  • has gone beyond elastic limit
  • Edge dislocation stays permanently to right
66
Q

Define work hardening?
(3-way + 2 features)

A
  • When lots of dislocation meet
  • Impedes each other
  • to stop dislocation propagation
  • Material = gets stronger
  • Larger stress to cause further strain
67
Q

Define grain boundaries?
(2 things + 2-way + 2 things)

A
  • Polycrystalline materials have this
  • Forms barriers to edge dislocation movement
  • Smaller grains = short distance travelled
  • … by the dislocation
  • Can make the material stronger
  • Dislocation can’t jump to next grain
68
Q

Define necking
(2-way)

A
  • The thinning of the cross-sectional area
  • of a material at the weakest point
69
Q

When does necking occur?
(2-way + 1 thing)

A
  • When material continues to be stretched
  • …. after reaching its ultimate tensile stress
  • Rapidly leads to materials failing
70
Q

Define ductile fracture?
(2-way)

A
  • Process of large strains and necking
  • leading up to the material failing
71
Q

What are the 3 ways to strengthen metals?

A
  • Grain size reduction
  • Work hardening
  • Foreign atoms
72
Q

Explain grain size reduction?
(Strengthening metals)
(3-way)

A
  • Smaller grains produce
  • more barriers
  • to dislocation movement
73
Q

Explain work hardening?
(Strengthening metals)
(3-way)

A
  • Plastically deforming metal
  • by creating a greater dislocation density
  • makes metal stronger
74
Q

Explain foreign atoms?
(Strengthening metals)
(2-way + 2-way)

A
  • Making metal alloys by….
  • introducing new elements into molten metal
  • Has effect of causing changes to lattice
  • impedes the movement of dislocation
75
Q

How is steel made through foreign atoms?
(2-way + 1 things’ definition)

A
  • Since adding similar sizes but different element atoms
  • to lattice distorts the lattice slightly
  • Interstitial takes place
  • (fitting in between the lattice atoms)
76
Q

Describe through labelled diagrams of the behaviour of ductile materials?

A

When the time calls…

77
Q

Show & draw me the stress-strain graph for ductile metals?
(4 stages w/ 2 having 1/3 things)

A
  1. Limit of proportionality
  2. Elastic limit
    ^^^ Yield strength
  3. Plastic region
    ^ first half = work hardening
    ^ second half = necking
    ^ peak = ultimate strength
  4. Fracture

When the time calls.

78
Q

What does it mean if brittle materials don’t undergo ductile fracture?

A

No plastic deformation within material

79
Q

What do brittle materials undergo?
(2 things + 2-way)

A
  • Elastic deformation
  • Usually failing within their elastic limit
  • They obey Hooke’s law….
  • up to their fracture point
80
Q

We’re at a considerably good spot

A

Lock in for A levels first. But it doesn’t hurt to be diligent

81
Q
A

AS levels Resurrection (22 decks)

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