Ib Physics Hl

Front 1

Displacement

Back 1

Distance in a given direction from a fixed origin. It is a vector.

Front 2

Velocity

Back 2

the rate of change with time of the displacement vector. It is a vector and is the gradient of a graph of displacement versus time.

Front 3

Speed

Back 3

distance travelled per unit time. It is a scalar quantity

Front 4

Acceleration

Back 4

the rate of change with time of the velocity vector. It is a vector and is the gradient of a graph of velocity versus time.

Front 5

Linear momentum

Back 5

product of mass and velocity. It is a vector

Front 6

Impulse

Back 6

total change in the momentum of a system as a result of a force acting on it. It is a vector whose magnitude is given by the area under a force versus time graph

Front 7

Power

Back 7

the rate at which work is performed; rate at which energy is tranferred

Front 8

Efficiency

Back 8

ratio of useful output work to input work

Front 9

mole

Back 9

amount of substance that contains the same number of molecules as there are atoms in 12 g of carbon-12

Front 10

molar mass

Back 10

mass of one mole of a substance

Front 11

avogadro constant

Back 11

number of molecules in one mole of a substance. 6.022 x 10^23

Front 12

Specific heat capacity

Back 12

the energy needed for unit mass to undergo a unit increase in temperature

Front 13

thermal capacity

Back 13

energy needed to raise the temperature of a specified object by 1K

Front 14

Specific latent heat

Back 14

energy required to melt or vaporize a unit mass at constant temperature

Front 15

pressure

Back 15

force normal to an area per unit area

Front 16

displacement (for an oscillating particle)

Back 16

the distance the particle moves in a particular direction from its mean position

Front 17

amplitude

Back 17

maximum displacement from equilibrium position

Front 18

frequency

Back 18

number of complete oscillations per unit time

Front 19

period

Back 19

time taken for one complete oscillation (cycle)

Front 20

phase difference

Back 20

an angle that represents the difference in motion between two oscillators

Front 21

simple harmonic motion

Back 21

the oscillatory motion of a system in which there is a fixed equilibrium position and the acceleration of the system is proportional to and opposite to its displacement away from the fixed equilibrium position; a = -ωx^2

Front 22

wavelength

Back 22

length of a full wave (crest to crest). It is the distance travelled in one period.

Front 23

wave speed

Back 23

the speed at which energy is transferred by the wave

Front 24

Intensity

Back 24

the rate of the energy transfer per unit area (proportional to square of the amplitude)

Front 25

electric potential difference

Back 25

the work done per unit charge in moving a small positive test charge from one point to another

Front 26

electron volt

Back 26

the work done in moving a charge of e through a potential difference of one volt

Front 27

electric current

Back 27

amount of charge per unit time that passes through the cross sectional area of a conductor

Front 28

resistance

Back 28

ratio of voltage across a conductor to the current through it

Front 29

emf

Back 29

work per unit charge done in moving a positive test charge across the terminals of a battery

Front 30

gravitational field strength

Back 30

the gravitational force experienced by a point test particle of unit mass

Front 31

electric field strength

Back 31

the electric force per unit charge experienced by a positive unit test charge

Front 32

magnitude of magnetic field

Back 32

the force on a unit charge moving at unit velocity at right angles to the magnetic field

Front 33

direction of magnetic field

Back 33

the direction that the north pole of a small test compass would point if placed in the magnetic field. The direction of the magnetic field B is at right angles to the force it exerts.

Front 34

nucleon number

Back 34

number of nucleons in a nucleus

Front 35

proton number

Back 35

number of protons in a nucleus

Front 36

neutron number

Back 36

number of neutrons in a nucleus

Front 37

radioactive half-life

Back 37

the time taken for one half of the number of radioactive nuclei in a sample to decay; the time taken for the activity of a sample to decrease to one half its initial value

Front 38

unified atomic mass unit (amu)

Back 38

1/12 of the mass of an atom of carbon-12

Front 39

mass defect

Back 39

difference between the mass of the nucleus and the sum of the masses of its constituent nucleons

Front 40

binding energy

Back 40

minimum energy required to separate a nucleus into free, unbound nucleons

Front 41

binding energy per nucleon

Back 41

minimum energy required to separate a nucleus into free, unbound nucleons divided by the number of nucleons

Front 42

energy density

Back 42

amount of energy that can be obtained from a unit mass of fuel

Front 43

albedo

Back 43

ratio of the intensity of radiation scattered and reflected from an object to the intensity of incident radiation

Front 44

surface heat capacity

Back 44

amount of thermal energy required for a unit surface area to undergo a unit increase in temperature

Front 45

coefficient of volume expansion

Back 45

fractional change in volume per unit temperature increase

Front 46

gravitational potential

Back 46

work done in bringing a point test particle of unit mass from infinity to a point in the gravitational field

Front 47

gravitational potential energy

Back 47

work done in moving two point masses, which are initially far apart, until they are separated by a distance r

Front 48

Magnetic flux

Back 48

product of the magnetic field strength and a cross-sectional area and the cosine of the angle between the magnetic field and the normal to the area

Front 49

magnetic flux linkage

Back 49

the product of the magnetic flux through a single turn and the total number of turns in a coil

Front 50

decay constant

Back 50

probability that a particular radioactive nucleus will decay per unit time

Front 51

capacitance

Back 51

amount of charge that can be stored on a body per unit electric potential

Front 52

quantum efficiency

Back 52

ratio of # of electrons emitted to number of incident photons

Front 53

magnification

Back 53

ratio of the length of the image on the CCD to the length of the object

Front 54

light year

Back 54

distance light travels in one year in a vacuum

Front 55

luminosity

Back 55

the amount of energy radiated by a star per second (or power radiated by a star)

Front 56

apparent brightness

Back 56

energy received per second per unit area of detector

Front 57

parsec

Back 57

distance to a star whose parallax is 1 arcsecond; 1 pc = 3.26 ly

Front 58

absolute magnitude

Back 58

apparent magnitude a star would have if observed from a distance of 10 pc

Front 59

critical density

Back 59

density of the universe for which expansion continues forever at a slowing rate and stops after an infinite amount of time; a universe with a density equal to the critical density is said to be "flat"

Front 60

proper time interval

Back 60

time interval between two events at the same point in space; it is the shortest time interval between the events measured by any inertial observer

Front 61

proper length

Back 61

length of an object in its rest frame; it is the greatest length measured by any observer

Front 62

rest mass

Back 62

mass of an object in its rest frame

Front 63

schwarzschild radius

Back 63

radius at which a spherical, non-rotating star becomes a blackhole