questions exam Flashcards
3 factors causes total stopping distance car to be greaer
- driver reaction time slower due to tiredness
-poor weather condition due to rain
-poor weather due to icy
How does feeling sleepy likely to affect drivers reaction time
it increases it
why driver drink alchol is likely to increase chance of being in accident
bceause the driver reaction time increases
(or cuase slower reaction time).
why did student use transparent block and not opqaue object
light will pass through an transparent block
simlarities of convex and concave lens
both are deminished
Driver see haqzard on road and use brakes to stop. Expalain the factor that affect the distance needed to stop a vehilce in emergencey
By condition on road surface as wet/icy road, and conditon of tyres of worns tyres and brales. These cause affect on friction by reduce between tyre and road, and increase braking this causes kinetic energy increase speed.
Give 1 simialrties and difference between orbit of earth moon and international space station
similar- both have cirucular orbit
differ- both have different orbital period
sun emits visble light, student concludes that visbile light is not abosrbed by the ozone layer. Tell one piece of evidence that show correct
our human eyes detect visble light so it must come through the ozone.
why does atmospheric pressure decrease as the student climbs higher
density of the air decrease and the mass of air above student decrease.
battery electric car need recharge. suggest 2 factor that affect the distance an electric car can travel before need rechargeing
capacity of battery and speed
slide is plastic, why does child become electrically charge when he goes down the slide
friction between child clothign and slide cause elctron transfer as 2 insulators are rubbed together.
state one factor that affetcs the braking distance of the car
weather conditon - wet/icy road
why and how does the kinetic energy of skier change as accerlate down the slide
increase gravitional potential energy to transofrmed to kinetic energy
what is kN worth
3kN=
3000
Student remove each piece of modelling clay from oil before dropping the next piece WHY
so that they dont build up at the bottom and all the peices fall the same distance
Describe how to use compass to plot the magnetic field pattern around bar magent
- Place bar magnet and compass on a peice of paper
- Mark where compass points to
- Keeping magnet in same place, move compass to marked point
4.Repet these steps until go back to magnet - Join up all the points
- add arrow in direction from north to south pole
- repet steps for above and below the bar magnet
how is velocity different to spped of aircraft when it travles constant velocity
velocity also includes direction
air is taken into the front of the engine and pushed out of the engine, explain the effect this has on egnine
a equal force from the air pushes on the engine in the opposite direction
describe lifecycle of star much more massive than the sun
- stars initially form from a cloud of dust and gas called nebula
2.the force of gravity pulls the dust and gas together to form a protostar - this provides enough thermal energy for the fusion og hydrogen nuclei to form helium nucli
- when outward pressure of nuclear fusion equals to the gravity pulling eveything inwards it is called main sequence star
- when hydrogen starts to run out, helium nuclei begin to fuse to form heavier elements up to iron and the star expand to form red super giant
- the star will eventually collapse and explode in a supernova
- this creates elememnts heavier than iron and distrivute them throughout universe
- this leaves bheind a neutron star or a black hole
ramp differ angle short and long ramp. Explain one advatge of use long ramp compare to small ramp
long ramp is at smaller angle so less force is needed to get up the ramp.
student tested three people, mean distance was 12.8 Why if all people who took the test may not be 12.8 mean distance
Three students tested are not typical
compare the model of solar system used now with the old model of solar system
similarities -
-Both model they orbit the moon, and planet in circular.
-The moon orbits the earth and there is only one sun.
Differences -
- in current model, planets orbit the sun whereas old planet orbit earth.
-There is shown of dwarf planet, whereas old model no dwarf planet.
-And 2 more planets.
wavelentgh of transverse wave -
wavelength = Q
amplitude of transverse wave -
amplitude = R divide 2
why is it important that new scientific observations are peer reviewed?
to check the observations are correct
give 2 ways that imaged formed by convex lens(larger, point up), is similar to image concave lens
upright
virtual
in tranverse wave, the direction of oscilloscope is …..
perpendicular to direction of energy transfer by wave
describe method to test, the black-coloured flask will emit more infrared radiation than the silver-coloured flask during 10mins of cooling. EQUIP - SILVER FLASK, BLACK FLASK, KETTLE COLD WATER
- heat wtaer in kettle
- add an equal volume of hot water to each flask
- insert a thermoter to each flasj
- record the inital reading from tempt of thereometer
- start stopclock
- record tempt after 10mins from both flask
- calculate change in tempt + compare the results to test hypothesis
when will flask emit infrared radition at the greatest rate and why - 1st/5th/9th min
1st cis there is greatest tempt difference between hot water and surrouding
describe what happen after main sequence of star become black dwarf
- star expand to become red super giant
- heavier elements are formed by fusion
- star shrinks to become a white dwarf
- star cools and stop emitting enrergy
describe what happens to star much bigger than sun after main sequence period
- the star expands to form a red supergiant
- outer layers explosde as a supernova
- elemts heavier than iron are formed
- become a nuetron star
- if mass larger enough it forms a black hole.
car stops as see fallen tree on road. explain what happen to brake distance if the spped doubles
double speed increase kinetic energy, kinetic energy increase by factor of 4. So work done by brakes to stop the car increase
what is difference between distance and displacement
distance is scalar, and displacement is vector.
total momentum of the 2 cars was not conserved. what does this mean
momentum before does not equal to momenutum after.
scientists want to develop seat belt that produce constant force throughout collision. Use idea of momentum why this is better for driver
reduce momenutum of drive so a smaller constnt force would be needed.
as aircraft moves, accerlation decrease even though the force is constant, why
as spped increases, air reistance increase. so resultant force is low
explain how london eye wheel can move at steady speed. capsules accerlate same time
velocity has direction , and accerlation occurs when the direction of each capsules changes.
another factor that can affect resultant force, and what effect it has on LONDON EYE WHEEL
greater the radius, the smaller the resultant force required
3 factors could cause total stoppoing distance to be greater
icy road on poor road condition.
worn tyres.
poor weather conditons raining
what happens when :
force are increased as pull thin strip of plasticine…
and when force are removed….
plastcinine stretches, and stays stretched
what happens when :
force increasred as push force on strong metal spring…..
when force removed…
spring compresses, and return to orginal length
what happens when :
force are increase as push force on thin plastic ruler….
when force removed..
ruler bends, and return to orginal shape.
why this statment wrong ‘ it will be much safer because driver can react much faster when driving faster than on road mile’
reaction time of driver does not depdend on speed of car
local council must decide whether to introduce lower spped limit - what evidence should council collect
monitor number of accident before and after speed limit.
and record number of vehicles.
student adjusted the ruler to make it vertical, why important (FORC 1 EXPERIEMENT - force and extension on sprng)
to reduce error in measuring the extension of the spring. As ruler of angle would make the measured extension shorter.
state 2 ways in whch shape of spring has change as extended
longer and increase gap between coil
what happens to kinetic energy of bus as it is braking
kineitc energy transferred by heating to the brakes.
applying brakes of the car cause the temperature of brakes increase, why
work done by friciton between brakes and wheels. causes decrease in kinetic energy and increase thermal energy
2 ways increase spanner turn effect
longer spanner and use greater force
use idea of moment to explain what happeens when child B move closer to pivo on see-saw. As child A and B are sat normlly
the clockwise moment of child B decreases making it less than the anticlockwise moment of child A. so child A move downwards
how could person lifting end of pole increase moment
increase the force exerted
use longer steel bar would be easier to remove tree stump why
force is applied further from the axis of rotation. so this increase moment of force
child pushes the brick to make it tilt. how far must the brick be tilted to fall over
line of action is outside baseline of brick
camera uses converging lens to form image, how image is different by lens on magnifying glass
in a camera the image is real not virtual. and inverted not upright.
radio wave and microwave are both electrogmagneti wave, travel same speed through air. Give 2 more properties that are same
tranverse
travel at same sppeed through a vacuum.
thermal image camera work better night than day to track criminals why
at night there is greater tempt difference between people and surroundings. so surrounding emit less infrared than in daytime.
describe how the wavelength of the water waves in ripple tank can be measured accurately
use metre ruler to measure across 10 projected waves and then divide by 10.
there is no air in space, astronout cant hear from outside spacesuit why
sound cant travel through a vacuum because there is no vibrate
it would not be safe to use x-ray to produce unborn child image why
x-ray are ionsing , they will cause mutations
describe difference between longitudinal and tranverse wave
the oscillation cause the wave. Tranverse wave is perpendicular to direction of energy transfer. Longitudiinal wave is parallel to direction of energy transfer.
describe feature of x-ray and ultrasound, and what happen when enter human born to show image of unborn baby
x-ray are electromagnetic wave and traverse wave.
-It is ionising radiation, the x-ray are absorbed by bone and transmitted by tissue.
ultrasound has a frequenecy above 20000hertz, and is longitudinal wave.
-reflected when it meets a boundary between 2 different media.
describe how radiowaves electromagnetic wave, is different from sound wave
it is transverse wave, can travel through vacuum and has greater frequencies. Travels at speed of light.
dots on balloon represent galaxies, first small then big balloon. give 1 strneght and 1 weakn representing idea of expanding universe
strnnght - the balloon expands as the dots get further apart
weakn - there is a limit to how far the balloon can expand
why cant scienctits answer question about ‘why was the universe created’
answer involves religious belief
how does red-shift from distant galaxies provide evidence for the beginning of the universe
red-shift shows galaxies are moving away from each other. More distant galaxies show bigger redhsift. so more distant galaxies are moving away faster
‘when observed from earth, there is an increase in the wavelength of light from distant galaxies’. Explain how this supports the big bang theory of the formation of universe
furthest galaxies show the biggest redshift. Meaning that the furthest galaxies are moving faster. So the universe is expanding
what is meant by ‘redshift’ and what does it tell us about distant galaxies
longer wavelength waves so galaxy moving away from earth
explain why sun will not go through supernova but star Mira will
only very massive stars become supernova. So mira is large enough but sun too small.
over billion of years the amount of hydrogen in star decrease why
converted into helium
explain how atoms of heavy element as gold AU, were formed
fusion of other elements during supernova of stars
explain how and when atom of different element distributed throughout universe
explostion of supernova at the end of the ‘life’ of stars.
describe how student measure frequenecy of water ripple
count number of waves that passes a point in a certain time
when paperclips pulled off magnet, they fall seperareltly. How could you test whether any paper clips have kept magnetism
bring paper clips all together and see if repel or attratcs.
explain why nebula stops collapsing as it becomes a main sequence star
gravity causes increase in temperature, this causes fusion of hygroden to form helium. until balance between gravity and fusion
2 advantages for adjustable lenses is glasses
dont need replacing if eye sight changes.
only need one pair.
advantage of use CT than ultrasound scan
CT scan give higher quality image
3 core cable must use and not 2 why
it must have earth wire to reduce risk of shock
disadvantage bury power cables underground
more difficult to repair
