question

Displacement

answer

Measured distance and direction from an object's starting point.

question

Speed

answer

The change in a moving object's displacement per unit time.

question

Acceleration

answer

Change in velocity per unit time

question

Terminal velocity

answer

The constant velocity reached when the force of gravity is equal to the force of drag.

question

Mass

answer

A measure of a body's inertia.

question

Inertia

answer

A body's reluctance to changes in its motion.

question

Gravitational force

answer

Accounts for planetary motion; weakest of four fundamental forces.

question

Weak interaction

answer

Responsible for radioactive decay; accounts for how the nucleus comes apart.

question

Electromagnetic interaction

answer

Force between particles' charges (coulombic attraction/repulsion).

question

Strong nuclear interaction

answer

Hold protons and neutrons together in the nucleus.

question

Newton's first law

answer

Every object continues in a state of rest of uniform motion in a straight line unless acted upon by an external force.

question

Equilibrium

answer

Static: object is at rest; not moving. Dynamic: object is moving with constant velocity.

question

Newton's second law

answer

The rate of change of linear momentum of a particle is directly proportional to the impressed force acting upon it and takes place in the direction of the impressed force.

question

Linear Momentum

answer

The product of an object's mass and its velocity.

question

Impulse

answer

The change in momentum per unit time.

question

Law of conservation of momentum

answer

If the total external force acting on a system is a zero then the momentum of the system remains constant (is conserved) or The momentum of a closed system is constant (conserved).

question

Newton's third law

answer

When a force acts on a body, an equal and opposite force acts on another body somewhere in the universe.

question

Work

answer

The amount of energy transferred to complete a task. or The product of the magnitude of a force and an object's displacement in the direction of that force.

question

Work done on a system

answer

Positive

question

Work done against a system

answer

Negative

question

Kinetic Energy

answer

The energy of a moving object.

question

Potential Energy

answer

Potential to do work based on an object's position.

question

Thermal Energy

answer

The sum of the total potential energy and the random kinetic energy of the molecules of the substance making up the system.

question

Chemical Energy

answer

Energy associated w/ electronic structure of atoms.

question

Nuclear Energy

answer

Energy associated with the nuclear structure of atoms.

question

Electrical Energy

answer

Energy associated with an electric current.

question

Elastic Collision

answer

Mechanical energy is not lost.

question

Inelastic Collison

answer

Mechanical energy is lost.

question

Power

answer

Rate of working; work done per unit time.

question

Efficiency

answer

The ratio of work going into a system to useful work coming out of a system.

question

Centripetal force

answer

A force that causes circular motion.

question

Examples of forces that provide a centripetal force

answer

Gravity; friction between road surface and a car's tires; magnets.

question

Temperature

answer

Scalar quantity that gives an indication of the degree of hotness or coldness of a body; the average KE per molecule of a substance.

question

Celsius scale

answer

0˚ = water's freezing point. 100˚ = water's boiling point.

question

Kelvin scale

answer

0 = absolute zero (-273.16˚ C). Kelvin is Celsius + 273.16.

question

Thermal energy can be transferred by:

answer

Conduction (a temperature difference causes the transfer of thermal energy from hotter to cooler areas). Convection (a temperature change causing the movement of fluid particles from a hot area to a cold area). Radiation (energy travelling through electromagnetic waves).

question

Mole

answer

The amount of substance that contains as many elementary particles as there are in 0.012 kg of carbon-12. Always state the element when measuring in moles.

question

Heat capacity

answer

The quantity of thermal energy needed to raise the temperature of a substance by one Kelvin.

question

Specific heat capacity

answer

The quantity of thermal energy required to raise the temperature of a unit of mass of a substance by one Kelvin.

question

Newton's law of cooling

answer

The rate of loss of heat of a body is proportional to the difference in temperature of the body and its surroundings.

question

Moving particle/ Kinetic theory

answer

-All matter is composed of extremely small particles -All particles are in constant motion -If particles collide with neighboring particles, they conserve their kinetic energy -A mutual attractive force exists between particles

question

Matter

answer

Anything that has mass and occupies space.

question

Properties of solids

answer

-Closely packed particles -Strong bonds between neighboring particles -Potential energy due to force of attraction between particles

question

Properties of liquids

answer

-Closely packed, strong bonds -Not rigidly held in position; bonds break and reform -Particles slowly and randomly move relative to each other -Variable shape -Slow diffusion -Kinetic Energy: vibrational, rotational, translational -Higher potential energy because spaces between particles are larger

question

Properties of gases

answer

-Widely spaced particles that only interact significantly when they collide or come very close together -Random zig-zag motion of particles causes gases to be dispersed throughout any container they are placed in. -Diffusion is quick -High translational KE due to higher mean speeds -Greatest PE due to greater distance between particles

question

Explaining phase changes with the moving particle theory

answer

As temp increases, vibrational KE increases; as KE increases, particles overcome forces binding them into a solid and begin spreading apart and slipping over one another, making a liquid. The same happens for gasses.

question

Evaporation

answer

A change from the liquid state to the gaseous state that occurs at a temperature below the boiling point. High KE particles escape binding forces but not all particles are at high KE.

question

Evaporative cooling

answer

As high-KE particles escape, total KE goes down causing a decrease in temp

question

Latent heat

answer

The thermal energy which a particle absorbs in melting, evaporation or sublimation and gives out in freezing, condensing or sublimating. -Doesn't produce change in temp

question

Latent heat of transformation

answer

The quantity of heat required to change one kilogram of a substance from one phase to another.

question

Pressure

answer

Force exerted over an area.

question

Ideal gas laws

answer

-Boyle: pressure of a gas at a constant temp is proportional to the gas' density -Charles Law: the volume of a fixed mass of gas at constant pressure is directly proportional to its absolute temperature.

question

Displacement (in SHM)

answer

The distance that an oscillating system is from its equilibrium position at any particular instant during the oscillation.

question

Amplitude

answer

The maximum displacement of an oscillating system from its equilibrium position.

question

Period

answer

The time it takes an oscillating system to make one complete oscillation.

question

Frequency

answer

The number of complete oscillations made by the oscillating system in one second.

question

Phase difference

answer

The relation between the displacements of two oscillating systems. In phase: always at the exact same displacement as each other (0˚) Anti-phase: always at opposite displacement (180˚)

question

Conditions of a simple harmonic oscillator

answer

Perfectly isochronous, whose amplitudes do not change with time.

question

Conditions required for SHM

answer

Acceleration of a system is directly proportional to its displacement from its equilibrium position and directed toward the equilibrium position.

question

Angular speed

answer

Number of radians through which a particle moves in one second.

question

Angular frequency (wumbo)

answer

ω=2πf or ω=2πf/T

question

Damped oscillations

answer

Oscillations for which the amplitude decreases with time.

question

Natural frequency

answer

The frequency that a system will naturally hold when you set it in motion.

question

Forced oscillation

answer

When you have to set a system in motion.

question

Resonance

answer

The maximum amplitude attained when an oscillatory system is driven at a frequency equal to its natural frequency.

question

Definition of a wave

answer

A means by which energy is transferred between two points in a medium without any net transfer of the medium itself.

question

Medium

answer

Substance/object the wave is traveling through

question

Transverse waves

answer

The source that produces the wave vibrates at right angles to the direction of travel of the wave. -Examples: seismic waves, em waves

question

Longitudinal waves

answer

The source that produces the wave vibrates in the same direction as the direction of travel. -Ex: sound waves

question

Crest

answer

The maximum height of the wave, i.e. the point at which the particles in the medium in which the waves travel have maximum displacement.

question

Trough

answer

The minimum height of the wave, i.e. the point at which the particles in the medium in which the waves travel have minimum displacement.

question

Compression

answer

The region of the wave where particles of the medium are \"bunched up.\"

question

Rarefaction

answer

The region of the wave where the particles of the medium are \"stretched out.\"

question

Intensity of a wave

answer

The energy that a wave transports per unit time across unit area of the medium through which it is traveling.

question

Wavelength

answer

The distance along the medium between two successive particles that have the same displacement.

question

Wave speed

answer

The speed at which energy is carried in the medium by the wave. -Depends only on the properties of the medium

question

Reflection

answer

When a wave reaches a barrier, it is reflected in the opposite direction. -The amplitude of a reflected wave is slightly less than that of the original wave because some energy goes into the barrier. -Law of reflection: Reflected waves are reflected at the same angle as the initial wave in the opposite direction.

question

Refraction

answer

The change in direction of travel of a wave resulting from a change in speed of the wave. -Determined by ratio of initial velocity to final velocity, and initial wavelength to final wavelength

question

Snell's Law

answer

When a wave is passing from one medium to another, the ratio of the sines of the angles Ø1 and Ø2 between the normal drawn at a right angle to the medium is constant. -This ratio is the refractive index of the second medium.

question

Diffraction

answer

When waves pass through a slit or any aperture, or pass the edge of a barrier, they spread out into the region that is not directly in the path of the waves.

question

Constructive interference

answer

Waves \"stack;\" two positive waves superpose to make a larger wave.

question

Destructive interference

answer

Waves cancel out; a positive wave and a negative wave superpose to decrease each other's effect .

question

Nodes

answer

The points at which destructive interference will cause a wave not to be displaced.

question

Antinodes

answer

The points of maximum constructive interference.

question

Coherent sources

answer

Sources that have the same frequency and are in phase.

question

Electric potential difference

answer

The power dissipated in a load per unit current in moving from one point to another. or The amount of electrical energy that is changed to other forms of energy when an amount of charge moves from one point to another. or The work done per unit charge in moving a positive charge from a point at higher potential to a point at lower potential.

question

Electron Volt

answer

The energy acquired by an electron as a result of moving through a potential difference of one volt.

question

Electric Current

answer

The rate at which charge flows past a given cross-section.

question

Resistance

answer

The ratio of the potential difference across the material to the current that flows through it.

question

Factors affecting resistivity

answer

length cross-sectional area resistivity temp

question

Ohm's law

answer

Provided the physical conditions such as temperature are kept constant, the resistance is constant, and therefore the potential difference is directly proportional to the current flowing. (only applicable to ohmic conductors) V = IR

question

Ohmic vs. Non-Ohmic resistors

answer

Ohmic resistors show a linear relationship between current and voltage, non-ohmic resistors do not.

question

Electric Power

answer

The rate at which energy is supplied to or used by a device. It is measured in Joules per second (Watts) P = IV

question

Electromotive force

answer

The work per unit charge made available by an electrical source.

question

Internal resistance

answer

Resistance within a circuit or power source.

question

Terminal voltage

answer

The measured voltage at the terminals of a power source.

question

Series circuit

answer

-All components have only one current pathway -All components have the same current through them -The sum of the potential drop across each component is equal to the emf of the power source -The total/effective resistance of a series circuit is the sum of the separate resistances

question

Parallel circuit

answer

-More than one current pathway -All components have the same potential difference across them -The sum of the currents flowing into any point is equal to the sum of the currents flowing out at that point

question

Voltmeter

answer

-Always connected across a device (in parallel) -Has very high resistance, takes very little current -Ideally would have infinite resistance with no energy dissipated in it

question

Ammeter

answer

-Always connected in series with a circuit -Has a very low resistance compared to the resistance of the circuit so that it will not significantly alter the current flowing in the circuit. -Would ideally have no resistance with no potential difference and no energy dissipated in it.

question

Potentiometer

answer

A variable resistor that determines the potential difference across an output transducer.

question

Newton's universal law of gravitation

answer

Every material particle in the Universe attracts every other material particle with a force that is directly proportional to the product of the masses of the particles and that is inversely proportional to the square of the distance between them.

question

Gravitational field strength

answer

The force exerted per unit mass on a particle of small mass placed at that point in the field.

question

Coulomb's law

answer

The force between two point charges varies with a force that is directly proportional to the product of the charges of the particles and that is inversely proportional to the square of the distance between them.

question

Law of conservation of charge

answer

In a closed system, the amount of charge is constant.

question

Conductors

answer

Have low electric resistance (contain electrons and positive and negative ions that are free to move).

question

Insulators

answer

Have high electric resistance (electrons are held tightly by the atomic nuclei and are not free to move through material).

question

Electric field strength

answer

The force per unit charge exerted on a positive test charge.

question

Magnetic field strength

answer

(Someone help me out here, I couldn't find a good definition in my notes)

question

Absorption spectra

answer

To change energy levels, electrons must absorb photons. This creates a spectrum of lines specific to elements.

question

Isotopes

answer

Forms of elements that are chemically identical but have different masses.

question

Neutron

answer

Uncharged particles in the nucleus that explain the existence of isotopes

question

Natural radioactive decay

answer

When elements emit radiation spontaneously (without external excitation).

question

Alpha radiation

answer

Emission of an alpha particle; range of 4 cm, easily stopped by a few sheets of paper (least penetrating, most harmful).

question

Alpha particle

answer

A helium-4 nucleus

question

Beta radiation

answer

Travels several meters; can penetrate aluminium sheets (medium level of penetration, medium harmfulness).

question

Gamma Radiation

answer

Short-wavelength em waves. Parent nuclide decays to an excited state of the daughter nuclide; daughter nuclide then drops to its ground state by emitting a photon. (Most penetrating, least harmful).

question

Half-life

answer

The time it takes the activity of a sample of the element to halve in value or the time it takes for half the atoms in the sample of element to decay.

question

Becquerel

answer

The number of atoms decaying per unit time.

question

Atomic mass unit (U)

answer

1/12 the mass of an atom of carbon-12; 1 U = 1.661*10^-27 kg

question

Einstein's mass-energy relation

answer

The mass of an object that is moving relative to an observer will be measured as greater than the object's mass at rest (m0).

question

Mass defect

answer

Represents the energy released in a reaction. If positive, reaction will take place spontaneously, if negative, reaction will require added energy.

question

Binding energy

answer

The energy required to separate the nucleus into it individual nucleons. or The energy that would be released in assembling a nucleus from its individual nucleons.

question

Fusion

answer

Arranging two nuclei to fuse together. Very high temps and pressures are required to overcome coulombic repulsion.

question

Fission

answer

A nucleus is split into two by emitting radioactive particles.

question

Energy degradation

answer

Energy that has been transformed into a less useful form.

question

Sankey diagram

answer

Thickness of arrows represent amount of energy used in each transformation

question

Non-renewable energy

answer

Source that is depleted when used, such as coal, oil, natural gas, etc.

question

Renewable energy

answer

A source that is permanent or that can be replenished as it is used.

question

Energy density

answer

The amount of potential energy stored in a fuel per unit mass or per unit volume.

question

Advantages/disadvantages of nuclear energy

answer

Advantages: -High energy density -More renewable than fossil fuels Disadvantages: -Hazards -Possible wartime applications -Radioactive waste

question

Advantages/disadvantages of hydropower

answer

Advantages: -No emissions -Renewable Disadvantages: -Large dams needed; causes population displacement -Possibility of dam failure

question

Advantages/disadvantages of geothermal power

answer

Advantages: -efficient, minimally destructive Disadvantages: -only useful in volcanic areas

question

Advantages/disadvantages of tidal power

answer

Advantages: -No emissions -Renewable Disadvantages: -Few areas have required tidal range -High construction costs

question

Advantage/disadvantages of solar power

answer

Advantages: -Renewable -Can be used nearly everywhere Disadvantages: -Expensive -Intermittent (no output at night or on cloudy days) -Small energy output per unit area

question

Advantages/disadvantages of wind energy

answer

Advantages: -Cheap -Clean -Renewable Disadvantages: -Expensive -Noisy

question

Fuel enrichment

answer

Thermal reactor fuel is a mixture of fissionable and fertile material enriched with U-235 and U-238 isotopes.

question

Moderator (in a nuclear reactor)

answer

Material that will slow down the fast neutrons to the speed of the slow thermal neutrons. (Placed around reactor core).

question

Control rods (in a nuclear reactor)

answer

Made of material that will absorb neutrons

question

Coolant (in a nuclear reactor)

answer

Removes thermal energy, converting water to steam. In this process, the water becomes radioactive.

question

Heat exchanger (in a nuclear reactor)

answer

System acting as a heat engine driven by chemical reactions or by nuclear reactions.

question

Active solar heating

answer

Using solar heaters to convert solar energy into heat energy (often used for domestic hot water).

question

Photovoltaic solar cells

answer

Photons from radiant energy excite electrons in a doped semi-conducting material, allowing electrons to flow in an external circuit to produce electrical energy.

question

Thermoelectric converters

answer

Bars of doped silicon are used to create an emf between hot and cold ends.

question

Ways of producing hydroelectric power

answer

Water storage in lakes, tidal water storage, pump storage.

question

Intensity of the Sun's radiation

answer

The amount of solar energy per second that falls on an area of 1 m2 of the upper atmosphere perpendicular to the Sun's rays.

question

Albedo

answer

The ratio between the incoming radiation and the amount reflected expressed as a coefficient or percentage.

question

Enhanced greenhouse effect

answer

Global warming caused by human production of excess greenhouse gasses

question

Black-body radiation

answer

Radiation emitted by a perfect emitter

question

Emissivity

answer

The ratio of the amount of energy radiated from a material at a certain temp and the energy that would come from a black body at the same temp.

question

Surface heat capacity

answer

The energy required to raise the temp of a unit area of a planet's surface by one degree kelvin.

IB Physics SL Paper 1+2 Definitions

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards