Answers

Answers: Level8

32. (a) (i) 1500 m/s or 1.5 km/s unit required for the mark 1
accept ‘2000 × 0.75 m/s’

(ii) 0.165 m or 16.5 cm unit required for the mark 1
or 165 mm accept ‘330 ¸ 2000 m’

(iii) shorter or less accept ‘lower or ‘smaller’ 1

(b) 4 m/s or 400 cm/s unit required for the mark 1

accept ‘5 × 0.8 m/s’ or ‘5 × 80 cm/s’

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33. greater less same

(a) length of year 1

length of day 1

radius of the planet 1

if more than one box is ticked in any row award no mark for that row

(b) 1100 N accept ‘100 × 11 N’ 1

· no winter and summer seasons accept ‘temperature the same all year’
or no seasonal variation or ‘no seasons’

· days and nights always the
same length

· Sun always directly above accept ‘Sun always follows the same
equator path across the sky’

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34. (a) (i) it moves across the pattern accept 'she can see it moving' or 'it 1
of stars or the sky appears to move' or 'it moves quickly'

do not accept 'it moves'

(ii)     it remains above a fixed            accept 'it stays in the same                       1
point on the Earth's surface       place in the sky'
or it does not appear to             or 'it can always be seen'
move across the sky                 do not accept 'it does not move'

(b) (i) no atmosphere or air accept ‘no clouds' or 'no light pollution' 1
pollution to distort the image

(ii) any one from 1

· difficult or expensive to get to for repairs or adjustments

· pictures have to be sent back to the Earth

· expensive to make or launch

· biceps and triceps both muscles are required for the mark

· quadriceps femoris and accept 'quads and biceps'
biceps femoris

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35. (a) any one from 1

· the permanent magnet attracts accept 'the magnet or magnetic
the iron plate field holds it’

· you cannot overcome the magnet accept 'the permanent magnet is still
working' or' the magnet is too strong'

(b) the field of the electromagnet accept 'the electromagnet acts against 1
opposes or cancels the field of the the magnet'
permanent magnet

do not accept ‘force holding door to plate is stopped’
or 'electromagnet repels plate' or 'magnetic field is
switched off’

· the permanent magnet still accept 'the permanent magnet will not be
attracts the iron plate affected by this'
or holds the door

· the electromagnet cannot cancel accept 'the electromagnet cannot
or oppose the magnetic field be turned on'

· the door cannot open unless accept 'the door can only open when
there is a current electricity or power is on'

(d)     the field of the electromagnet              accept 'the electromagnet reinforces        1
reinforces the field of the                    the magnet' or 'the electromagnet also
permanent magnet                              pulls the iron plate'

do not accept 'poles now the wrong way round' or 'poles are now the same way round’

(e) one mark is for the explanation that current causes the electromagnet to work; the other mark is for the repercussions of a current failure

any one from 1

· the electromagnet will hold the accept 'it only works when the magnet is
door shut only when there is switched on’
current

· if there is no current, the
magnetic field stops

· it will be possible to open the do not accept 'it is not as safe or secure’ 1
door in a power failure or by cutting
the wire or if the battery is flat

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36. (a) (i) it decreases accept 'it is fast at the beginning and 1
then slows down'

accept 'it is constant at first and then decreases'

do not accept 'it increases at first and then decreases'

(ii) it decreases 1

(b) units are required for each of the calculation mark

either

· maximum possible acceleration accept '4000 ÷ 1000 = 4 m/s2’ 1
is 4 m/s2 or 4 m s–2

· average acceleration is 4 m/s2 accept '24 ¸ 6 = 4 m/s2' 1
or 4 m s–2

· average acceleration will be less 1
than the maximum due to friction
or due to the mass of the driver

· maximum possible acceleration accept '4000 ÷ 1000 = 4 m/s2’ 1
= 4 m/s2 or 4 m s–2

· maximum speed after 6 s is accept ‘4 × 6 = 24 m/s’ 1
24 m/s or 24 m s–1

· actual speed will be less than this 1
due to friction or due to the
mass of the driver

· maximum possible acceleration accept '4000 ÷ 1000 = 4 m/s2’ 1
= 4 m/s2 or 4 m s–2

· minimum time to reach accept '24 ÷ 4 = 6 s’ 1
24 m/s is 6 s

· actual time will be more than 1
this due to friction or due to the
mass of the driver

· average acceleration is 4 m/s2 accept '24 ÷ 6 = 4 m/s2’ 1
or 4 m s–2

· average force is 4000 N accept '4 × 1 000 = 4000 N’ 1

· force from the engine must be 1
more than this to overcome friction

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37. (a) (i) A 1

(ii) D 1

(b) (i) any one from 1

· electrons are rubbed accept ‘negative charges are rubbed
off the cloth off the cloth’

·   electrons are transferred      do not accept ‘charge is rubbed
from the cloth to the             off the cloth’
sulphur

do not accept ‘charge is transferred from the cloth to the sulphur’

(ii) any one from 1

· the charges repel each accept ‘the charges repel each other’
other to the edge of the circle

·   the charges flow to the         do not accept ‘the charges flow
edge of the circle where       to the edge of the circle’ or
the sulphur is a insulator       ‘it becomes conducting’

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38. (a) any one from 1

· sections become longer

· more spread out

· broader accept ‘pattern further apart’

do not accept ‘becomes blurred’

(b) any two from 2

· wider areas

· areas overlap or have blurred edges

· less strongly magnetised areas accept ‘weaker magnetic field’

do not accept ‘it will be weaker’

accept ‘you would need more tape to get a sharp pattern’ or more tape would have to be used’

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39. both the time and the explanation are required for the mark

(a) a time between 3.30 pm and 6.00 pm accept any time between 1
or later afternoon or sunset or dusk 15.30 and 18.00 hours

         because Britain is moving from the           accept as explanations 'because Britain
day side of the world to the night side       is going from day to night or from light
                                                              into darkness'

or 'because it is nearly nighttime' or 'because the Sun is in the West'
accept 'because it is sunset or dusk' as an explanation provided that it is not also given as the time.

(b)     (i)      Britain is in the same                 do not accept 'Britain is in the same         1
position in both diagrams           position relative to the Sun or to the
                                               sunlight' or 'from the position of Britain'

(ii)     it is dusk in one position             accept 'it is morning in one diagram        1
and dawn in the other                and evening in the other' or 'the Sun is
                                               shining from different sides'

accept ‘in position A it is dawn' or any time between 3.30 am and 6.00 am

do not accept a restatement that it is dusk in position B

do not accept'it is light in one position and dark in the other' or 'Britain is spinning towards the Sun in A and away from it in B'

(iii) 0.997 days the unit is required for the mark 1

accept more decimal places
accept '182.5 × 24 ¸ 183 hours'
accept '23.9 hours' or '23 hours 56 minutes'

(c) (i) the time for the Moon to accept 'it turns on its axis once 1
rotate on its axis is equal to during a complete orbit of the Earth'
the period of its orbit

40. (a) 1

either the dashed construction lines or the dotted lines ....... must be drawn

accept a combination of construction lines and arcs of circles, drawn with a compass, which enable the image to be located correctly
construction lines may be dotted, dashed or continuous

accept a dot instead of the letter I to indicate the position of the image

award no mark if construction lines are not drawn or if the position of the image is not very close to the correct position

(b) (i) it is in the same place accept 'it does not' 1

(ii) it is closer to the mirror accept 'closer to the eye' or 'it is closer' 1

construction lines may be dotted, dashed or continuous

accept a dot instead of the letter I to indicate the position of the image award no mark if construction lines are
not drawn or if the position of the image is not very close to the correct position above the fish

(d) below the apparent position of accept 'below the image' or ‘lower in the 1
the fish water' or ‘below where they see the fish'

accept ‘in front of the image'

do not accept 'below the fish'

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41. (a) any one from

·   the current flows in opposite           do not accept 'the currents in A and B      1
directions so there is no                  cancel out so there is no field'
magnetic field                                or 'the coils are wound in opposite
                                                    directions'

· because the two magnetic fields do not accept 'they cancel out'
or forces cancel out

(b) answers may be in any order

         there is no current in coil A                 accept 'there is current in coil B only'      1
                                                         or 'the currents in the coils are different'
                                                         or 'coil A will lose its magnetic field'

do not accept 'there is current in coil B'

         the magnetic fields no longer cancel    accept 'the iron core becomes                  1
                                                         magnetised' or 'the magnetic fields
                                                         are different'

the armature will be attracted 1
or pulled towards the core

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