Physics Terms

Front 1

Displacement

Back 1

The distance moved in a particular direction.

S

Front 2

Velocity

Back 2

The Rate of Change of displacement.

V or U

Front 3

Speed

Back 3

The Rate of Change of Distance

V or U

Front 4

Acceleration

Back 4

The Rate of Change of Velocity

a

Front 5

Instantaneous v. Average

Back 5

The instantaneous value of a magnitude is taken at one particular time, while the average value is taken over a period of time.

Front 6

Relative Velocity

Back 6

Velocity in one frame of reference compared with a different frame of reference.

Front 7

Inertial Mass

Back 7

Ratio of force applied on a body divided by acceleration caused by the force.

Front 8

Gravitational Mass

Back 8

The property of an object that determines how much gravitational force it feels when near another mass.

Front 9

Linear Momentum

Back 9

The product of mass and velocity.

p=mv

Front 10

Impulse

Back 10

Product of force multiplied by the time the force acts.

Ft=p

Front 11

Work

Back 11

The product of force and displacement if they are both in the same direction

W = Fs

Front 12

Kinetic Energy

Back 12

Energy due to Motion

Front 13

Power

Back 13

The Rate at which energy is transfered

Front 14

Efficiency

Back 14

A ratio of the useful energy to the total energy transferred.

Front 15

Newton's First Law of Motion

Back 15

A body remains at rest or in uniform velocity unless acted on by an unbalanced force.

Inertia

Front 16

Newton's Second Law of Motion

Back 16

The rate of change of the momentum of a body is proportional to the resultant force and occurs in the direction of the force.

Front 17

Newton's Third Law of Motion

Back 17

When two bodies A and B interact, they exert an equal and opposite force on each other.

Front 18

Law of Conservation of Linear Momentum

Back 18

If no external force acts on the system, the total momentum of the system is conserved.

Front 19

Temperature

Back 19

A measure of the average kinetic energy of the molecules of a substance.

Front 20

Conduction

Back 20

Thermal energy transfer through matter as a result of collision of vibrating molecules of its neighbor.

Front 21

Convention

Back 21

Thermal energy transfer between two points due to a bulk of matter. E.g hot fluid expands, gets less dense, rises, and creates a current. (can only take place in fluids or gasses).

Front 22

Radiation

Back 22

Energy transfer due to the radiation of electromagnetic waves emitted by any body above 0 Kelvin.

Front 23

Heat Capacity

Back 23

Amount of energy needed to raise the temperature of a body by 1 Kelvin ( ).

Front 24

Specific Heat Capacity

Back 24

Energy required to raise the temperature of one unit mass by 1 Kelvin ( ).

Front 25

Specific Latent Heat of Fusion

Back 25

Energy required to change one unit mass of solid into liquid at its melting point.

Front 26

Specific Latent Heat of Vaporization

Back 26

Energy required to change one unit mass of liquid into gas at its boiling point.

Front 27

Mole

Back 27

The amount of substance that contains as many elementary units as there are atoms in 0.012 kg of the isotope carbon-12 (mol).

Front 28

Molar Mass

Back 28

The Mass of 1 Mole of the Substance in Question

Front 29

Avogadro's Constant

Back 29

The number of molecules in one mole of a substance. ( ).

Front 30

Thermodynamic System

Back 30

Set of objects that we wish to consider. Everything else is referred to as its environment.

Front 31

Boyle's Law

Back 31

For a fixed mass of gas pressure is inversely proportional to volume if temperature stays constant.

Front 32

Pressure Law

Back 32

For a fixed mass of gas pressure is directly proportional to the absolute temperature if volume stays constant.

Front 33

Charles Law

Back 33

For a fixed mass of gas volume is directly proportional to absolute temperature if pressure stays constant.

Front 34

Wave Pulse

Back 34

One disturbance.

Front 35

Transverse Waves

Back 35

Oscillations are at right angle to the direction of energy transfer. The top of the wave is called a crest and the bottom a trough.

Front 36

Longitudinal Waves

Back 36

Oscillations are parallel to the direction of energy transfer which is transferred by compressions and rarefactions.

Front 37

Displacement (Waves)

Back 37

Displacement from equilibrium position of a particle.

X

Front 38

Amplitude

Back 38

Maximum displacement from the mean position.

A

Front 39

Period

Back 39

Time taken (in seconds) for one complete oscillation.

T

Front 40

Frequency

Back 40

The number of oscillations that take place in one second. Measured in Hertz.

f

Front 41

Wavelength

Back 41

Shortest distance along the wave between two points that are in phase with one another.

Lamda

Front 42

In Phase

Back 42

Two points that are moving exactly in step with one another.

Front 43

Wave Speed

Back 43

The speed at which the wave’s front pass a stationary observer.

Front 44

Refraction

Back 44

As a plane wave incident at an angle on the boundary between two media, the transmitted wave will change its direction and its speed.

Front 45

Coherent Sources

Back 45

Two sources with the same frequency and a constant phase difference.

Front 46

Diffraction

Back 46

When waves spread around obstacles.

Front 47

Interference

Back 47

The resulting wave of two waves which meet and interfere with each other, and can be determined by the Principle of Superposition.

Front 48

The Doppler Effect

Back 48

Change of frequency of a wave as a result of the movement of the source or the movement of the observer.

Front 49

Snell's Law

Back 49

The ratio of the wave speeds in two different media, as a wave travels from one medium into another.

Front 50

Huygen's Principle

Back 50

Each point on a wave front acts as an individual point source to produce new circular waves.

Front 51

Principle of Superposition

Back 51

The overall disturbance at any point and at any time where two waves meet is the vector sum of the disturbance that would have been produced by each of the individual waves.

Front 52

Electric Field

Back 52

Force per unit charge acting on a positive test charge. It is a vector quantity.

Front 53

electric Potential Energy

Back 53

The work required to bring a small positive test charge from infinity to a particular point in an electric field. Measured in Joules (J).

Front 54

Electric Potential

Back 54

The work required per unit charge to bring a unit positive test charge from infinity to a particular point in an electric field. Measured in Joules per Coulomb ( ).

Front 55

Electric Potential Difference (Voltage)

Back 55

The work done in bringing a unit positive test charge from one point to another in an electric field. Measured in Joules per Coulomb ( ).

Front 56

Electric Current (Conventional)

Back 56

The rate of flow of charge (positive to negative). C/t

Front 57

Electric Current (Actual)

Back 57

The rate of flow of the electrons (negative to positive).

Front 58

Drift Velocity

Back 58

The average velocity given to an electron by the potential difference across a conductor.

Front 59

Resistance

Back 59

The opposition to the flow of electric current.

R

Front 60

Ampere

Back 60

The current in each of two parallel infinite long wires, 1 meter apart in a vacuum, which experiences a force between them of , is 1 Ampere.

Front 61

EMF

Back 61

Electro Motive Force

It is the work per unit charge made available by an electrical source.

Front 62

Coulomb's Law

Back 62

The force between two charges is directly proportional to the product of the two charges and is inversely proportional to the square of the distance between them.

Front 63

Ohm's Law

Back 63

The current flowing through a conductor is directly proportional to the potential difference applied across it if the temperature remains constant.

Front 64

Nuclide

Back 64

The name given to a particular nucleus (one whose nucleus contains a specified number of protons and neutrons).

Front 65

Isotope

Back 65

Nuclides of the same element (same proton number) but different number of neutrons and atomic mass.

Front 66

Nucleon

Back 66

Particles inside the nucleus (protons and neutrons).

Front 67

Mass Number

Back 67

The sum of protons and neutrons in an element.

Front 68

Atomic Number

Back 68

Number of protons in the nucleus (determines the element).

Front 69

Alpha Particle

Back 69

Helium nuclei (He) emitted from a larger nucleus.

Front 70

Beta Particle

Back 70

Electrons emitted from the nucleus during neutron decay together with an anti-neutrino.

Front 71

Gamma Radiation

Back 71

Released during decay of an element from an excited state to a lower energy state to become more stable.

Front 72

Half Life

Back 72

Time taken for half the number of nuclides present in a sample to decay.

Front 73

Unified Atomic Mass Unit

Back 73

One twelfth the mass of a carbon-12 atom.

u

Front 74

Mass Defect

Back 74

Difference between the mass of a nucleus and the masses of its components.

Front 75

Binding Energy

Back 75

Amount of energy that is released when a nucleus is assembled from its component nucleons.

Front 76

Nuclear Fission

Back 76

Nuclear reaction whereby large nuclei are induced to break up into smaller nuclei and release energy in the process.

Front 77

Nuclear Fusion

Back 77

Nuclear reaction whereby small nuclei are induced to join together into larger nuclei and release energy in the process.

Front 78

Radioactive Decay

Back 78

Happens in unstable nuclei. Involves one of the three possible form of radiation: alpha, beta or gamma decay.

Front 79

Strong Nuclear Force

Back 79

Short range attractive force between protons, neutrons and protons, and neutrons and neutrons.

Front 80

Emission Spectra

Back 80

The light an element emits which is not continuous and contains characteristics color lines which correspond to that element.

Front 81

absorption Spectra

Back 81

Light is shone through an element in the gaseous state with black characteristics lines which correspond to electrons jumping between allowed electron energy levels.