Definitions U1 Flashcards

1
Q

Hookes law

A

The extension of a spring is directly proportional to the force acting on it up to the limit of proportionality

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

Stress

A

Applied force per unit area of cross section

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

Ultimate tensile stress

A

Max stretching force per unit area without material breaking

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

Strain

A

Ratio of change in length to original length of specimen

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

Young’s modulus

A

Measure of stiffness of material, got by ratio of stress divided by strain

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

Microscopic

A

Small scale

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

Macroscopic

A

Large scale

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

Isothermal

A

Constant T

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

Boyles law

A

For fixed mass of gas at constant T the V is inversely proportional to the p

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

Charles law

A

For fixed mass of gas at constant pressure V is directly proportional to the T in Kelvin

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

Pressure law

A

For fixed mass of gas at cons V the p is directly proportional to the T in kelvin

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

Mole

A

Amount of substance which has as many particles as there are in 12g of C-12

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

Specific heat capacity

A

Thermal energy required to raise the T of a body of mass 1kg by 1K

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

STP standard temperature and pressure

A

0 degrees Celsius
1x10 ^5 Pa

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

Centripetal

A

Centre seeking

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

Angular velocity

A

Rate of change of angular displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Simple harmonic motion

A

Acc is directly proportional to the displacement
Acts towards fixed position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Damping

A

Resistive force which opposes motion and so causes the amplitude to decrease

19
Q

Resonance

A

External force drives another to oscillate with greater amplitude at specific frequencies

20
Q

Free vibrations

A

No energy transferred to or from system, amplitude is fixed

21
Q

Forced vibrations

A

Forced to oscillate at frequency of external oscillator

22
Q

Isotope

A

Atoms of element with same number of protons but different number of neutrons

23
Q

Ionisation

A

Converts atom, molecule or substance into ion(s) by removing 1 or more electrons

24
Q

Background radiation

A

Ionising radiation present in the environment

25
Q

Exponential decay

A

Decay that falls by fixed fraction per unit time

26
Q

Activity

A

Number of degradations per second in sample, measured in Bq

27
Q

Decay constant

A

The fraction of total number of nuclei present to decay per unit time

28
Q

Half life

A

Time for number of radioactive nuclei to decay to half its original value

29
Q

Unified atomic mass

A

1/12 mass of one atom of C-12
u = 1.66x10^-27

30
Q

Electron volt

A

Unit of energy equal to work done by electron accelerating it through a pd of 1V

31
Q

Binding energy

A

Energy required to split up a nucleus into its nucleon parts

32
Q

Binding energy per nucleon

A

Av energy required to remove a single nucleon from its nucleus

33
Q

Mass defect

A

Difference between mass of separated nucleus and combined mass of nucleus

34
Q

Nuclear fission

A

Splitting of large nucleus into lighter nuclei with release of energy

35
Q

Nuclear fusion

A

Joining of 2 light nuclei to form one heavier more stable nucleus which releases energy

36
Q

Conditions required for fusion

A

Nuclei must be confined within a finite Volume at sufficient temperature to increase chances of collision with enough energy to overcome the electrostatic repulsion

37
Q

D-T reaction

A

2,1 H + 3,1 H -> 4,2 He + 1,0 n + 17.6MeV

38
Q

Internal energy

A

Sum of ke and pe in a molecule

39
Q

Kinetic theory ideal gas assumptions
F e v V t

A

No intermolecular forces
V and t are negligible
v is constant
Energy is conserved as collisions are elastic

40
Q

Critical size, what should be greater than the critical size? What should be less than the critical size?

A

Minimum size of nuclear fuel to sustain a chain reaction
Total amount of fuel
Amount of fuel in each rod

41
Q

Moderation

A

Slows fission neutrons (doesn’t absorb them) so that U-235 absorbs them

42
Q

Control rods
Material

A

Inserted to control number of neutrons that are able to cause further fission
Boron/Cadmium

43
Q

Cooling system (substance)

A

Water or CO2 is circulated around the fuel rods to cool them. Energy is passed to a heat exchanger where it is used to power a steam turbine

44
Q

Reactor shielding (material)

A

Thick steel and several metres of concrete surround reactor, preventing harmful radiation from escaping