Physics Definitions Flashcards

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1
Q

Note what is meant by the ‘Elastic Limit’ of a spring

A

The maximum load the spring can experience and still return to its original length when the deforming force is removed

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2
Q

Define strain and state it’s expression and unit

A

Strain is the ratio of the change in length of a specimen to its original length
It’s expression is ε
It does not have a unit

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3
Q

Define Young’s Modulus and state it’s expression and unit

A

Young Modulus is a measure of the stiffness of a material, it is the ratio of stress to strain within the limit of proportionality
It’s expression is E
It’s unit is Nm^-2 or Pa

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4
Q

State Hooke’s Law and it’s equation

A

The extension of a spring, x, is directly proportional to the force applied, F, provided the limit of proportionality is not reached/exceeded

F=kx

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5
Q

Define the term “Limit of Proportionality”

A

The point beyond which Hooke’s Law is no longer true when stretching a material

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6
Q

Define Stress and state it’s expression and unit

A

The applied force per unit area of cross section
It’s expression is σ
It’s unit is Nm^-2 or Pa

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7
Q

State Charles Law

A

For a fixed mass of gas at a constant pressure, the volume is directly proportional to the temperature in Kelvin
V/T=k

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8
Q

State Boyles’ Law

A

For a fixed mass at constant temperature, the volume is inversely proportional to the applied pressure.
pV=k

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9
Q

State the Pressure Law

A

For a fixed mass of gas at constant volume, the pressure is directly proportional to the temperature in Kelvin
P/T=k

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10
Q

Define Ultimate Tensile Strength

A

The maximum stretching force per unit area without the material breaking

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11
Q

Define Mole

A

The mole is the amount of substance which contains as many particles as there are in 0.012kg of carbon 12

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12
Q

Define microscopic

A

Small scale

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13
Q

Define Macroscopic

A

Large scale

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14
Q

Define Isothermal

A

Constant temperature

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15
Q

What is STP

A

Standard temperature and pressure, taken as 0 degrees Celsius and 1x10^5 Pa

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16
Q

Define Specific Heat Capacity

A

The thermal energy required to raise the temperature of a body of mass 1kg by 1K

17
Q

Define Centripetal

A

Centre seeking

18
Q

Define Angular Velocity

A

The Rate of change of angular displacement

19
Q

What happens to a system undergoing Simple Harmonic Motion?

A

In SMH the acceleration is directly proportional to the displacement and is always directed towards the fixed position

20
Q

What is Damping

A

A resistive force which opposes motion and so causes the amplitude of a system to decrease

21
Q

How does Resonance occur

A

Resonance occurs when a vibrating system or external force drives another system to oscillate with greater amplitude at specific frequencies

22
Q

What are Free Vibrations

A

Vibrations in which no energy is transferred to or from the system, thus amplitude remains fixed

23
Q

What are Forced Vibrations

A

When a system is forced to oscillate at the frequency of an external oscillator (giving it energy) it undergoes forced vibrations

24
Q

What is an Isotope?

A

Isotopes are atoms of an element with the normal number of protons and electrons, but different number of neutrons

25
Q

Define Ionisation

A

Converting a substance into an ion or ions, typically by removing one or more electrons

26
Q

Define Background Radiation

A

The ionising radiation present in the environment

27
Q

Define Exponential Decay

A

Decay in which the amount falls by a fixed fraction per unit time

28
Q

Define Activity

A

The number of disintegration’s per second in a sample, measured in Bq

29
Q

What is a Decay Constant

A

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

30
Q

What is a Half-Life

A

The time for the number of radioactive nuclei present to decay to half its original value

31
Q

Define Nucleon

A

Any constituent that exists in the nucleus

32
Q

Define Unified Atomic Mass (u)

A

1/12 of the mass of one atom of carbon 12, u = 1.66 x 10^-27kg

33
Q

What is an Electron Volt (eV)

A

A unit of energy equal to the work done on an electron in accelerating it through a potential difference of 1 volt, 1eV = 1.6 x 10^-19 J

34
Q

Define Binding Energy

A

The energy required to split up a nucleus into its constituent nucleons

35
Q

What is Binding Energy per Nucleon

A

The average energy required to completely remove a single Nucleon from its nucleus

36
Q

Define Mass Defect

A

The difference between the mass of the separated nucleus and the combined mass of the nucleus

37
Q

Define Nuclear Fission

A

The splitting of a heavy / large nucleus into lighter nuclei with the release of energy

38
Q

Nuclear Fusion

A

The joining of 2 light nuclei to form 1 heavier more stable nucleus which releases energy

39
Q

What conditions are required for Fusion?

A

The nuclei must be confined within a finite volume at a sufficient temperature to increase the chances of collision with sufficient energy to overcome the electrostatic repulsion