EXAM Flashcards
Explain 1 disadvantage caused by solar cells only facing one direction.
Solar cells don’t track the sun and won’t generate as much electricity.
When ball hit ground, energy is transferred from ball to earht. Explain the energy transfer.
Velocity after bounce is decreased, with the loss of kinetic energy. Means the ball has lost its energy as height from top of bounce is less than height dropped.
nuclear fusion is the joining together of …..
during nuclear fusion the totoal mass of the particles….
nuclei, decrease
Why were modeles tested befre starting to build?
To devlop understanding of process and to assess safety risk.
Explain 1 environmental effetc of genertaing electricity using fossil fuel
realses carbon dioxide which causes global warming.
Explain the effect of 2 other factors on braking distance of car. ( no speed include)
Braking distance of car can be effected due to, poor road surface as wet or icy road, amking the poor condiiton on tyres to be worn brakes. This is because decreased fricitin as it slows tyres to brake.
When rider reach bottom of slide, sled decerlates and stop. Give 2 factors that affect how far the sled will move before it stops.
Speed at bottom of slide and fricition between sled and ground.
LED lamps are much more effcient than filament lamp means?
LED lamp waste a smller proportion of input energy than filament lamp.
Why might filamenet inside a lamp melt when the lamp is first switched on?
The current goes too high.
Connecting 2 reisotrs in parall circuit, what happen to total resistance of circuit
Decrease because totoal resistance is always less than smallest indiivudal resistance.
2 envirnemntal issue caused be genertaing electricty using nuclear power ststaion
Waste is radioactive and is toxtic
why can parallel circuit operate wither 2 swithc
because switch in parallel so closiing either switch completes the circuit.
why the fricition between sock and carpet make studen charge
transfer of electrons fro the carpet to the student.
Negative charge student touch a metal tap and recive electric show why
because there is P.D between student and the tap which causes charge to transfer from the stuent.
expain one envuronemntal problem cause when electrictty is generated by buring coal
release carbon dioxide causes global warming.
why did studetn insulate beaker of water in specific heat coaicty experinent.
to reduce energy trasfer to the surroduniing
rider reach bottom of slide, sled declertaes and stop, 2 reason that affect how far the sled will move before it stops.
speed at bottom of slide and friciton between sled and ground.
the cells were put into torch the wrong way round, why the troch didnt work
there is no current in diode inthe revser direcetion because has very high resistance in reverse direction
describe use equipment on syringe and pressure gauge to obtain data
- record intial volume of air
- record the intial pressure
- push the plunger of syringe to decrease volume of air
- read nd record new wavlue of pressure guage and volume
- rpet for different vlumes
describe method student on investigate how quickly kettle could increase the tempt of water
- measure mass of water use balance
- measure inital tempt of water use thermoter
- pour water into kettle
- place thermoter in water]
- switch kettle on
- take recording of tempt of water every 5secon
- record with stopclosk
for safety, it is important that the bungee cord used is appropiate for students weight, why?
bungee rope may snap and extend too much
Explain what led to the plum pudding model of the atom being replaced by the nuclear model of atom
The alpha particle scattering experiment have led changes as alpha particle directed at gold foil. Most of alpha particles pas staright through so msot of atom is empty space. Plum pudding model has mass spread throughout atom and change spread.
explain why people should be encouraged to use energy efficent electrical device
more effiecent devices waste less energy which minismise the electricity demand
some energy from wind used to rotate is wasted. engineer oils mechanical parts wind trubine how does oiling affet efficicency of wind turbine
efficiecny increases because amount of wasted energy would decrease. Lubrication of oil mean less fricition
what is 696 MW
696 000 000
how will increase resistance of varibale resistor in series affect:
- current in circuit
- p.d across lamp
- total resit
decrease, decrease, increase
which particle in atom was discovered first
electron
what is half-life
time taken for half the nuclei in a sample to decay
what is nuclear fusion fuel
and nuclear fission fuel
hydrogen, uranium
student could not make valid conclusion from the result about how different insluating matierla affect the energy transfer. explain 2 ways that student could imporve this
use the same number of layers of insulation so that the tempt difference can be compared.
use the same volume of water so the same area of bottle surface is heated by the water.
why use bar chart
is labels/catergories/// is not numerical values
B student move toward river and cord stretchs, how does B compare energy store with A standing still. - less than A or more than A
grav potential engerg-
kinetic -
elastic-
less than at A, more than A, more than A
Bungee A spring const - 78.4 , extens- 36, B= 82, ext-24, C= 84.5, ext-12.
Why will C have smaller extension than A
greatest spring constant
particles in gas move with ….
move in …
range of speeds, random direction
volume gas increase, pressure decreases, tempt same. How does increase volume effect:
- meantime betwen collosion of particles
- mean dstant between particles
- mean speed of particles
- increase
- increase
- same
why student left thermometer in iron block for few mins before record inital tempt
so the thermoter tempt was the same as tempt of iron block
explain change in arrangement and movement of soild and liquid particles as ice melt and tempt increase to 5 degree
particles in soild are in regular pattern and liquid are in random arrangement. Particles in soild are visbrating about dixed postion when heated, and lqiuid are mvoing freely. So, as the ice changes to water the tempt remain constant and potentail energy of particls increase. As the water warms, particles move faster so does the kinetic energy. This increases internal energy of the total kinetic and potentail energy of all the particles.
describe the action of the 5A fuse in a circuit
if currrent is above 5A, the fuse will melt and cause it to break the circuit
Explain functions of live, neural , earth wire
live wire carries p.d of 230v from the main supply. Neutral wire completes the circuit. Earth wire is safety wire to stop casing appliances becoming live
Transformer p.d steps up the 25kV to 400kV. Explain why
Increasing p.d decrease the current. So the smaller current means less energy changed to thermal energy in cabels
Explain how the balloon become negatively charged when rubbed on jumoer and what happens to jumoer
Electrons are transferred from jumoer to balloon. Jumper now positively charged because looses electrons
explain in terms of particles, why gases are easy to compress
large gaps between particles, so easy to push particles close together
fox have large ears, explain how size of ears help it to keep cool in hot desert
fox ears have large surface, this radiates heat and keep blood cooler
difference of soild and gas on space, movement and force.
info soild - fixed shape, diffuclt to compress(squash)
gas - spread, fill entire container, easy to compress(squash)
Soild particles are close together in a fixed position, it is strongly held together. So no room for particles to move hence hard to compress.
- Soild vibrates in fixed postion and strong force of attraction.
Gas particles are far apart, random directions, and have space between each particle. Hence easy to push particles closer.
-Moves randomly have have no force of attraction.
describe characteristic of alpha and beta strcutre, penetrate through air and material, deflection electric field
Alpha - consist of helium nuclues + 2 protons and neutrons.
-Absorbed by thin paper +skin
-Penetrate a few cm in air.
Beta - consist electron from nucleus comes from.
-Pass through thin metal plate.
-Travel further than alpha particle in air, several metres in air.
ALPHA AND BETA deflected in opposite direction in an electric field.
why is it impossible for alpha and beta decay produce same element.
alpha and beta produce different number of atomic number, so number of prtons determine the elemnt.
why does beta decay not change mass number
number of neutrons decrease by 1, number of protons inceease by 1
neutral atom has no overall charge, explain in terms particles.
ELCTRON - -1, PROTONS +1 ,NEUTRONS 0
an equal opposite charge because number of protons equal to number of electrons
why people may be concerned about safety of eat irridated foods
people may link the use of radioation with illness
give reason why farmers, consumers, hsop owerners, may want foood to be trated with radiaiton
less likley to not get food poisoning.
one way process of nuclear fusion differs from process of nuclear fission
nuclei are joined not split
describe what happens to nuclues of atom during nuclear fission
splits into 2 smaller parts and 2 nuetron
why person may recive higher than avergae dose of radiation from bakcground source
working at nuclear power stations
Briefly what is difference between nuclear fission and nuclear fusion
nuclear fission split atomic number, nuclear fusion is joining 2 atomic nuclei to form a larger one.
how does fox with small ears survive in cold weather
fox with smaller ears have thicker fur so this minimises energy transfer
why national grid use high voltage with small current to transfer electricuty
smaller current reduces heating effect in cables, so less energy wasted in cables.
describe energy transfer that happen when ball hit wall
kinetic energy transfers to thermal energy
1 safety precaution to take when use electric heater
do not touch heater when switched on
describe 1 ways radioactivity can be used to disagnose cancer, and 1 radioactivity to treat cancer
Tracer is radioactive source.
-injected into patient and travel around body.
-emits gamma radiation
-so can be dected outside of the body with gamma camera
Radiotherapy to treat cancer cells by use of X-ray.
- x-ray kills cancer.
explain why student should open switch after each reading on resistance experiment
resistor would get hot if current left on, so it increases resistance
householder always fill electrical kettle to top, even when for 1 small cup. how is this wasting money
bigger volume takes more time to boil. so more energy transferred and this costs more money.
