Physics Standard Level Ib

Front 1

Displacement

Back 1

Linear distance of the position of an object from a given reference point

Vector (s)

Front 2

Velocity

Back 2

Rate of change of displacement

Vector (v or u)

Front 3

Acceleration

Back 3

Rate of change of velocity

Vector (a)

Front 4

Speed

Back 4

Rate of change of distance

Scalar (v or u)

Front 5

Newton's 1st Law of Motion

Back 5

An object remains stationary or at a constant velocity if there is no resultant force acting on the object.

Front 6

Condition for translational equilibrium

Back 6

There is no resultant force on the object in any direction

Front 7

Newton's 2nd Law of Motion

Back 7

A resultant force acting on a body equals the rate of change of momentum of the body

Force = mass x acceleration

Front 8

Linear momentum

Back 8

Product of mass and velocity

p = mv

Front 9

Impulse

Back 9

Product of force and time
Change in momentum

∆p = F x t

Front 10

Law of conservation of Linear Momentum

Back 10

If the net external force acting on a system is zero, then the total momentum of the system is constant.

Front 11

Newton's 3rd Law of Motion

Back 11

When body A exerts a force on body B, body B exerts an equal and opposite force on body A.

Front 12

Principle of Conservation of Energy

Back 12

The total energy of a closed system is constant.

Front 13

Power

Back 13

Rate of transforming energy or rate at which work is done.

Front 14

Efficiency

Back 14

Ratio of useful power of the system to the input power

Front 15

Temperature

Back 15

Is a measure of how hot or cold an object is. It determines the direction of thermal energy transfer between two objects. It measures the average random kinetic energy of the molecules of an ideal gas.

Front 16

Kelvin

Back 16

Is the measure of temperature using a scale beginning on absolute zero.
Absolute zero is where the molecules have no kinetic energy and thus no movement.

Front 17

Relationship between Kelvin and Celsius

Back 17

K = C +273

Front 18

Internal energy

Back 18

The total potential energy and random kinetic energy of the molecules of the substance.

Front 19

Kinetic energy of molecules

Back 19

Arises from the random movement of the molecules.

Front 20

Potential energy of the molecules.

Back 20

Arises from the forces between molecules

Front 21

Mole

Back 21

Has as many molecules as there are atoms in 12g of Carbon (12C).
1 mole contains 6.022 x 10^23 atoms

Front 22

Molar mass

Back 22

The mass of one mole of substance in grams

Front 23

Avogadro's constant

Back 23

The number of atoms in 12g of Carbon (12C)
6.022 x 10^23

Front 24

Specific heat capacity

Back 24

The amount of thermal energy required to raise the temperature of one unit mass by one degree

C = Q/m∆T

Front 25

Thermal capacity

Back 25

The amount of thermal energy required to raise the temperature of an object by one degree.

C = Q/∆T

Front 26

Specific latent heat

Back 26

Thermal energy absorbed or released per unit mass of a substance at a constant temperature during a change of phase.

Front 27

Pressure

Back 27

Force per unit area

Front 28

Assumptions of the kinetic model of an ideal gas

Back 28

1) Perfectly elastic
2) Spheres
3) Identical
4) No forces between molecules

Front 29

Thermal equilibrium

Back 29

Heat flows from the hot body to the cold body until they are at the same temperature.

Front 30

Displacement (SHM)

Back 30

Instantaneous distance of the moving object from its mean position (m)

Front 31

Frequency

Back 31

Number of oscillations completed per unit time (Hz)

Front 32

Time Period

Back 32

Time taken for 1 complete cycle
T = 1/f

Front 33

Amplitude

Back 33

Maximum displacement from the equilibrium position

Front 34

Phase Difference

Back 34

Difference in phase angle between 2 oscillations with the same frequency.

Front 35

Simple Harmonic Motion

Back 35

When the acceleration on the body is directed towards equilibrium and is proportional to its displacement from equilibrium.

Front 36

Damping

Back 36

It involves a force that is always in the opposite direction to the direction of motion of the oscillating particle. The force is a dissipative force, which reduces the total energy of the system.

Front 37

Natural frequency

Back 37

The frequency at which an object will vibrate if "disturbed"

Front 38

Forced oscillations

Back 38

If an object is forced to oscillate by a periodic external force (not at its natural frequency), either a very large increase in amplitude is seen or the body vibrates with maximum amplitude.

Front 39

Travelling waves

Back 39

Progressive/ travelling waves transfer energy and there is no net motion of the medium through which the wave travels.

Front 40

Displacement (waves)

Back 40

Distance of an oscillating particle in a given direction from its mean.

Front 41

Amplitude

Back 41

The maximum displacement of a particle from its rest/equilibrium

Front 42

Frequency

Back 42

Number of oscillations per unit time

Front 43

Time Period

Back 43

Time for one complete cycle

Front 44

Equilibrium position

Back 44

Where the particle would rest if not disturbed

Front 45

Intensity

Back 45

The rate of flow of energy across the cross sectional area perpendicular to the direction of wave propagation.

Front 46

Wavelength

Back 46

Distance moved by wavefront during one oscillation of the source/ distance between consecutive neighboring crests

Front 47

Wavefront

Back 47

Are always at 90degrees to the direction of travel of the wave and are separated by wavelength.

Front 48

Wave speed

Back 48

Rate at which energy is transferred/ distance traveled by a wave front per unit time

Front 49

Electromagnetic waves

Back 49

All travel at the same speed in free space, 3 x 10^8 m/s

Front 50

Snell's Law

Back 50

The ratio of the velocities of the waves in two media is equal to the ratio of the sines of the angles of incidence and refraction of the rays.

sin i / sin r = v1 / v2

Front 51

Refractive Index

Back 51

The ratio of the velocity of the wave in two media

Or the ratio of angle of incidence to the angle of refraction

Front 52

Principle of Superposition

Back 52

When the paths of two waves of the same type coincide, the resultant displacement is the sum of the 2 individual displacements at that point.

Front 53

Constructive Interference

Back 53

When two waves meet, the resultant displacement is greater than that of an individual wave.

Front 54

Destructive Interference

Back 54

When two waves meet, the resultant displacement is less than that of an individual wave.

Front 55

Conditions for Constructive Interference

Back 55

If two waves of the same type have a path difference of a whole number of wavelengths, nλ, or have a phase difference of 2nπ

Front 56

Conditions for Destructive Interference

Back 56

Path or Phase difference of:
(n+1/2)λ or (2n+1)π

Front 57

Electric Potential Difference

Back 57

Work done per unit charge to move a small positive charge between two points

Front 58

Electronvolt, eV

Back 58

Work done in moving an electron through a p.d. of 1V

Front 59

Current

Back 59

Rate of flow of charge

I = Q/T

Front 60

Resistance

Back 60

The rate at which a charge can flow through a conductor depends on the resistance (which is dependent on size and material)

R = ρL/A

More current flows through a short fat conductor than a long thin one

Front 61

Ohms Law

Back 61

The current is proportional to the voltage across it at constant temperature for Ohmic materials.

V = IR

Front 62

Electromotive force, emf

Back 62

Total electrical energy supplied by the cell per unit charge as it flows through the cell

Front 63

Newton's Universal Law of Gravitation

Back 63

Every single point mass attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of their separation.

Front 64

Gravitational Field Strength

Back 64

Force per unit mass on a small mass placed at the point

Front 65

Electric Charge

Back 65

There are two types: positive and negative

Front 66

Law of Conservation of Charge

Back 66

The total charge of a closed system is constant

Front 67

Coulomb's Law

Back 67

F = kQ/r^2
The force experienced by 2 point charges is directly proportional to the product of their charge and inversely proportional to the square of their separation.

Front 68

Electric Field Strength

Back 68

Force per unit charge felt by a positive test charge placed in a field.

Front 69

Moving charges

Back 69

give rise to magnetic fields:
e.g. Moving charge/ current in a wire creates a magnetic field around the wire.

Front 70

Magnitude of field

Back 70

B = FIlsin(angle)

Front 71

Direction of field

Back 71

From n to S or the direction of force acting on small point north pole of a compass