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Terms in this set (277)
What does a shaper gradient on a velocity time graph mean?Greater accelerationWhat does the negative gradient on a velocity time graph mean?DecelerationWhat does a horizontal line on a velocity time graph mean?Constant speedWhat does 0 velocity mean on a velocity time graph?It is stationaryWhat does the area under the line on a velocity time graph represent?Distance travelledWhat does a curved line on a velocity time graph mean?Acceleration is changingWhat is average speed used for?When the speed changes during the motionHow to work out average speed?With overall distances and timingsHow can you determine constant speed?Measure distance travelled
Use stopwatch for time taken
S = d/tHow to find average speed?- work out total distance travelled
- find time taken for whole journey
- speed = d/tHow to find speed using light gates:- set up two, one at the start and one at the end
- measure distance between them
- as the object passes through the first, it will measure time taken to reach the second
- speed = d/tWhat is acceleration due to gravity?9.8 m/s^2What is Newton's first law?An object has a constant velocity unless acted on by a resultant forceWhat is acceleration?The change in velocity over timeIf a resultant force acts on an object it will...AccelerateWhat is happening when an object accelerates?The direction or speed (or both) of an object changesWhat happens to an object if the resultant force is zero?- no acceleration
- moving at a constant velocity or at rest.What is Newton's second law?Force = mass x accelerationHow is weight measured?Using a force meter or weighing scalesThe greater the gravitational field strength....The greater the weightWhen an object is moving in a circle it is accelerating as....The speed is constant. The direction is always changing.
So velocity is always changing.
So it is acceleratingWhen an object is moving in a circle there must be a..... which supplies this acceleration. This is called.....Force / centripetal force.Centripetal force is directed towards...The centre of the circleWhat is Newton's third law?Every action force has an equal and opposite reaction force.What is the reaction force for the weight for a book on a table?The reaction force on the book by the tableWhat is the reaction force of two marbles colliding?- the force exerted by one marble onto the other is the same as the force from the otherMomentum is always..... in a collision, when there are no.....Conserved / external forcesMomentum equationMomentum = mass x velocity
p = mvTotal momentum before =total momentum afterWhen two marbles collide, each will have the ............. and....... The collision.Before / afterForce and momentum equation:Force = change in momentum / time takenWhat is human reaction time?A delay between a human observing an event and actingWhat experiment can measure human reaction time?The ruler drop experimentHow to do the ruler drop experiment:Someone else holds a ruler just above your open hand
They drop it at a random time
Record the distance from the bottom of the ruler to the point where it was caught
Average this by 1cm being 50 milliseconds.What are vehicle stopping distances?Once seeing a hazard you react.
During the reaction time you travel X meters. This is thinking distance.What happens after the thinking distance?You react. Causing the car to slow down and stop over Y meters.
This is the braking distance.What factors can affect thinking distance?Speed
Concentration
Tiredness
Influence of drugs/alcoholWhat factors can affect braking distance?Speed
Poor road conditions
Mass (more passengers)The greater the speed....The greater the thinking distancewhat are the dangers of large decelerations?- it takes place in a very short time
- force = mass x acceleration so there is a great force exerted on the car + passengers.
- this force can cause injuryBefore the crash you have a large.... and after the crash you have....Momentum / no momentumWhy is there such a great force in the crash?Force = change in momentum / timeThe work done to stop a vehicle is equal to....The initial KE of the vehicleWhy is the work done to stop the vehicle equal to the initial KE?All the kinetic energy the car had has to be transferred to friction for it to stop.Braking distance is directly proportional to....Initial velocityChange in gravitational potential energy =mass x gravitational field strength x change in vertical heightGPE =MghWhat is GPE measured in?JoulesKE =1/2mv^2What is the KE equation used for?To calculate the amounts of energy associated with a moving objectWhat do energy transfer diagrams show?Energy input and energy output and the forms that the energy takes.
Includes waste output energyHow do motors waste energy?Through heatHow does energy change when an object is projected upwards?Ke transferred to GPE and vice versa as it falls back downHow does energy change when an object is projected up a slope?KE transferred to GPEHow does energy change when a vehicle is slowing down?KE transferred to heat through brakesHow does energy change when water is boiled in a kettle?Electrical energy to thermalWhat does the conservation of energy mean?The total energy of an isolated system remains constant.A closed system has no...External forces acting on it.In a closed system the total energy... regardless of the energy transfer that takes place.Never changesIn a closed system...No energy is lostIn mechanical processes, energy transferred can cause... so energy is dissipated to the......A rise in temperature / surroundingsWhen energy is dissipated to the surroundings...The process is wastefulWhat are the common forms of waste energy?Light, sound and heatHow to reduce waste energy:- lubricant systems
- thermal insulationHow do buildings prevent heat loss?Thicker walls
Using cavity wall insulationEfficiency equation:Efficiency= Useful energy output/total energy inputHow can efficiency be increased?- reducing waste output
- recycling waste outputWhat are some energy sources?Fossil fuels, nuclear fuel, wind, tidal, solarFossil fuels are an example of....Non renewable energy.Waves transfer energy without....Transferring matterWavelength definitionDistance between the same points on two consecutive wavesAmplitude definitionDistance from equilibrium line to the maximum displacement (crest or trough)Frequency definitionNumber of waves that pass a single point per secondPeriod definitionTime taken for a whole wage to completely pass a single pointWavefront definitionThe plane in which the wave travels (e.g direction)Frequency wavelength equationVelocity = frequency x wavelengthWhen frequency increases...Velocity increasesWhen wavelength increases...Velocity increasesPeriod is........... to frequencyInversely proportionalTransverse waves have...Peaks and troughsExamples of transverse waves...Light, any electromagnetic wave, seismic S waves, water wavesIn transverse waves vibrations are at....Right angles to the direction of travelHow to measure sound in air:Make a noise at 50 m from a solid wall + record time for the echo to be heard
Then use S = d/tHow to measure sound in air using microphones:- have two microphones connected to a data logger at a large distance apart
- then record the time difference between a sound passing from one to another
- speed = d/tHow to find velocity of ripples on a water surface:Use a stroboscope which has the same frequency as the waves
Then measure the distance between the fixed ripples + use v=fxlambdaHow to calculate velocity of ripples on a water surface using a pencil + paper =- move a pencil along the paper at the same speed as a wavefront
- then measure the time taken to draw this line + the length of the line
- then used speed = d/tWhat is refraction?Waves passing from one medium to anotherWhat will happen when waves pass into a more optically dense medium (air to glass) ?- the wave will be refracted at the boundary and will change direction to bend towards the normalWhat happens to speed, wavelength and energy when waves pass into a more optically dense medium?Speed decreases
Wavelength decreases
Energy is constantWaves will only reflect off a...Flat surfaceThe ....... the surface, the stronger the reflected wave is.SmootherRough surfaces ........ the light in all....... so appear ..... and not reflective.Scatter / directions / mattThe angle of incidence =angle of reflectionWaves will pass through a ...... material.TransparentThe more transparent the material the more light can....Pass throughGlass ...... visible lightReflectsP waves are...LongitudinalS waves are...TransverseWhat are the two types of seismic waves?P and SP waves can pass throughsolids and liquidsS waves can only pass through...SolidsThe normal is a ......... which is ...... to the surface.Dashed / perpendicularAll angles are measured from the....NormalThe angle of incidence is....The angle entering the rayThe angle of reflection is....The angle exiting the rayAngle of incidence =angle of reflectionIf light enters a ........ material is bends ........ the normal.Denser / towardsIf light enters a less dense marker all it bends .......... the normal.Away fromWhen does total internal reflection occur?When light passes from a denser medium into a less dense medium. When the angle of incidence is equal to the critical angle.What happens when the angle of incidence is equal to the critical angle?Total internal reflection occurs. The refracted ray will pass along the boundary and not exit the medium.What happens when the angle of incidence + critical angle are larger?The light internally reflects back into the glass.What are gamma rays used for?Sterilising food and medical equipment, cancer treatmentWhat are X-rays used for?Observing internal structure of objects, airport/medical scannersWhat are ultraviolet rays used for?Security marking, fluorescent lamps, disinfecting waterWhat are visible light rays used for?Vision, photography, illuminationWhat are infra red waves used for?Cooking, night vision equipment, optical finresWhat are microwaves used for?Communication and cooking foodWhat are radio waves used for?Communications and satellite transmissions.Higher frequency electromagnetic waves have more ......, so exposure can transfer too much ...... to cells. This causes ........Energy / energy / mutationDangers of X rays/Gamma raysmutation or damage to cells in the bodyDangers of ultraviolet waves?Damage to surface cells, can lead to skin cancer, and blindnessDangers of infra red wavesSkin burnsDangers of microwavesInternal heating of body tissueWhat is the order of electro magnetic waves?RMIVUXGThe order of electromagnetic waves is decreasing in .......... but increasing in....Wavelength / frequencyAll electromagnetic waves are.... and travel at the same speed....Transverse / in a vacuumAll electromagnetic waves transfer ........ from...... to....Energy / source to observerOur eyes can only detect.....Visible lightMaterials interact differently with electromagnetic waves depending on.....The wavelengthAs wavelength decreases.....Frequency must increaseAs frequency increases.....Energy of the wave increasesIf angle is less than critical angle....Light refracts away from normalIf angle is equal to critical angle...Light passes along the boundaryIf angle is more than critical angle...Light reflectsWhat is an atom?A positively charged nucleus surrounded by negatively charged electronsAn atom is made ofprotons, neutrons, electronsWhat is the relative mass of a proton?+1What is the relative charge of a proton?+1What is the relative mass of a neutron1What is the relative charge of a neutron0What is the relative charge of an electron?-1What is the mass of an electron?0.0005Atoms of the same element have the same number of...ProtonsNeutral atoms have the same number of....Electrons and protonsWhat are isotopes?Atoms of the same element with different numbers of neutronsWhat are examples of isotopes?Carbon 12, 13, 14What is the mass number?Number of protons and neutronsThe proton number is....Below the mass numberRadiation is emitted ...... from an.....Randomly / unstable nucleusWhat are the forms of decay?Alpha, Beta, Gamma, NeutronsAn alpha particle is a...Helium nucleusAn alpha particle has a charge of..+2Alpha particles are highly....IonisingWhat is the penetrating power of an alpha particle?Very low, only 10cm in airGamma radiation has low....Ionising powerGamma radiation has high....Penetrating powerBeta particles have medium....Ionising and penetrating powersBeta particles charge-1What is background radiation?The low-level radiation that's around us all the timeHow does cosmic microwave background radiation support the Big Bang theory?It is the remains of the initial heat from the Big Bang that is now spread thinly across the whole universe.What are examples of background radiation?Cosmic rays and underground rocks.What are the two methods of measuring radioactivity?Using photographic film or a Geiger-Muller tubeHow is background radiation measured with photographic film?- film is initially white
- film goes darker when it absorbs radiationHow is photographic film used in everyday life?Worn as badges by people who work with radiation to monitor their exposure.How is a Geiger Muller tube used to measure radioactivity?- a tube which can detect radio action
- each time it absorbs radiation, it transmits an electrical pulse to the machine which produces a clicking sound.
- the greater the frequency of clicks, the more radiation is present.An alpha particle has a mass number of...4After decay, nuclei often have.... Which is released as...Excess energy. / gammaWhat is the activity?Number of decays in a sample per secondWhat are the units of activity?Becquerels (Bq)What is the half-life?The time taken for half the nuclei/activity in a sample to decay.The activity decreases ............. over time.ExponentiallyWhat are some uses of radioactivity?Smoke alarms
Irradiating food
Sterilisation of equipment
Diagnosis and treatment of cancerWhat are the dangers of ionising radiation?- can cause mutations in organisms
- can damage cells and tissue
- can cause problems when disposing of it.Why is radiation with a short half life less harmful?- is initially very radioactive but quickly dis down
- so less of a long term riskWhy is radiation with a long half life harmful?- remains weakly radioactive for a long period of time,What is an example of radiation with a long half life?Americium. Does not need to be replaced has a half life of 432 yrs. is weakly ionising so not harmful.What are safety measures for radiation?- limiting patient does
- limiting risks to medical personnel.What is contamination?- lasts for a long period of time
- source of radiation is transferred to an object.What is an example of contamination?Radioactive dust settles on your skin, your skin becomes contaminated.What are the characteristics of irradiation?Lasts for a short period of time
Source emits radiation which reached the objectWhy are medical items sometimes irradiated?To kill bacteria on its surface but not to make the tools radioactive.Describe how a uranium 235 nucleus undergoes fission?- it absorbs a slow moving neutron and becomes unstable
- the nucleus is split into two smaller daughter nuclei.
- more neutrons and energy are released.Describe how nuclear fission results in a chain reaction:- the released neutrons are absorbed by other uranium nuclei which causes them to split.
- a chain reaction occurs if at least 1 of these neutrons goes on to cause a fission.The sun and other stars use....... To release energy.Nuclear fusionDescribe nuclear fusion:Fusion of two small nuclei which form a large nucleus. Energy is released in the process.When nuclear fusion occurs the mass of the products is slightly....... Than the total mass of the original nuclei.Smaller.Fission definitionProcess of a nucleus splitting into two smaller nuclei after absorbing neutrons.Radioactive decay is when...An unstable nucleus decays into two smaller nuclei.Fusion definitionThe process of small nuclei being fused together to form a heavier nucleus.What is the role of a moderator in a nuclear reactor?Slows down the emitted neutrons so they can be more easily absorbed. Usually made of graphite/water. Makes it more efficient.What is the role of control rods in a nuclear reactor?Absorbs excess neutrons, preventing a runaway chain reaction.What happens to the heat energy from the chain reaction?Is absorbed by water (coolant) which evaporates into steam and is used to turn a turbine.
The turbine turns the generator which generates electricity.What is the role of shielding around a nuclear reactor?Absorbs radiation preventing it escaping.What are some advantages of nuclear power?Produces little CO2. Releases a lot of energy. No atmospheric pollution. Produces a lot of electricity.What are some disadvantages of nuclear power?Nuclear meltdowns.
Nuclear waste.
Nuclear energy is non renewable.Why does nuclear fusion happen at low temperatures and pressures?- both nuclei are positively charged and like charges repel.
- at high temps and pressures the nuclei have enough kinetic energy to overcome the electrostatic repulsion.
- so they can get close enough for fusion to occur.The universe is a collection of billions of....GalaxiesA galaxy is a large collection of billions of...StarsOur solar system is part of the galaxy:The milky wayWhy does the size of gravitational force change between planets/moons?-size depends on the mass of the objects (planets) and the distance between them.Gravity is different on...Other plants, the moon and the earth.Gradient causes planets and comets to...Orbit the sunGravity causes moons and artificial satellites to...Orbit the earthCentripetal force keeps...The moon moving in a circular orbitDescribe how the moon orbits the sun:Sort of zigzags around the circular orbit of the earth around the sunWhy does mercury have the shortest year?- it is closest to the sun
- the radius of its orbit is smaller + force of gravity is larger
- so orbit speed is largerThe orbit of a comet is...Highly ellipticalComets originate from...The outer edges of the solar systemComets orbit in a different....Plane from planets.Red light has a..........Longer wavelength than any other coloirViolet light has a ....Shorter wavelength than any other colour of light.What is a red shift?When the dark lines in the spectrum of a galaxy are shifted towards the red part of the spectrum. Makes the light waves longer.Red shift occurs when...Distant galaxies are moving away from usThe......a galaxy is moving away from us, the bigger....Faster/ it's red shift isFor two distant galaxies at different distances, the one with the smaller red shift is moving....SlowerThe universe is expanding and all distant galaxies are moving....Away from each otherWhat is the Big Bang theory?Theory that the universe began as a tiny hot dense region.
It then expanded quickly in an event known as the Big Bang.How does redshift support the Big Bang theory?- provides evidence that the universe is expanding.
- the further away galaxies are, the faster they are moving.
- supports idea that universe is expanding from a single point.What is the Doppler effect?A change in frequency and wavelength. When an object is moving towards an observer the waves are shifted to a higher frequency and a shorter wavelength.What is the Doppler equation?change in wavelength/observed wavelength = velocity of a galaxy/speed of lightSpecific heat capacity equationChange in thermal energy = mass x specific heat capacity x temperature changeWhat is true in a series circuit?Closed circuit
The current is the same everywhereWhat is true in a parallel circuit?- current split into multiple paths
- total current into a junction = total current in each of the branches
- voltage is the same across each branchWhat does a diode look like?A sideways triangle with a line at the topWhat does a thermistor look likeA rectangle with a diagonal line going through it?What does a LED look like?A diode with two arrows going upwards from itWhat does a variable resistor look like?a rectangle with an arrow throughCurrent is the....Rate of flow of chargeVoltage is the...Energy transferred per unit charge passedHow to remember voltage equation?Evil Queen Victoria
E = QVWhy is a voltmeter connected in parallel?Measures the potential distance across the componentIn a series circuit, current is...The same all the way round the circuitThe voltage across the resistors adds up to...The voltage across cellsThe larger the resistor...The bigger the voltage across itIn a series circuit, the total resistance is...The sum of the values of the individual resistors.In a series circuit there is the same...Current through each componentIn a series circuit the total voltage of the supply is...Shared between the componentsIn a series circuit the total resistance is the...Sum of the resistance of each component.In a parallel circuit the voltage across each branch is...The sameIn a parallel circuit the total current through the whole circuit is the....Sum of the currents through the separate branches.In a parallel circuit the resistance of two resistors in parallel is...Less than the resistance of either of the individual resistors.Quiche is tasty equationQ = ItThe volt is...A joule per coulombIn a series circuit if a lamp breaks or a component is disconnected then...The circuit is broken and all the components stop workingIn a parallel circuit if a lamp breaks or a component is disconnected then...The components on different branches keep workingWhat circuits do we use in our homes?ParallelAs the voltage increases the current...IncreasedEnergy is transferred into the bulb ...... and is converted into ...... energy and ..... radiation.Electrically / thermal / lightAs the voltage increases the temperature of the bulb..... this ..... the bulb's resistance.Increases/ increasesWhat do lamps and LEDs indicate in a circuit?The presence of currentWhy is there resistance in metals?Due to electrons colliding with ions in the latticeWhat is Ohms law?Current is directly proportional to voltage and inversely proportional to resistance
V = IRThe resistance of a wire increases if....The length increases
The cross sectional area decreasesAs the temperature increases the resistance of a thermistor....DecreasesAs the light intensity increases the resistance of the LDR...DecreasesWhen the voltage is negative the diode has a very large..... and no current....Resistance / flowsA diode only allows current to flow in....One directionDensity equationmass/volumePressure equationforce/areaPressure difference equationheight x density x gravitational field strengthTotal initial momentum is equal to....Total after momentumTotal momentum before the collision =total momentum after collisionWhy is momentum conserved?- Newton's 3rd law
- these equal + opposite forces cause equal and opposite changes in momentumThe stopping distance is the sum of...The thinking distance and the breaking distance.Definition of a longitudinal waveVibrations are parallel to the direction of travel of the wave.Definition of transverse waveVibrations are perpendicular to the direction of travel of the wave.Longitudinal waves have...Compressions and rarefractions
Sets found in the same folder
TormeadPhysicsTeacher
03 Stellar Evolution
23 terms
02 Radioactivity
46 terms
02 fission and fusion
18 terms
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