Download (a) Satellite A is

Satellites Examination Questions
1) H The diagram shows two satellites in different orbits around
the Earth.
Satellite B
North Pole
Equator
Satellite A
South
Pole
= orbits of satellites
(a) Satellite A is in geostationary orbit.
(i) Explain what is meant by a “geostationary” orbit.
.........................................................................................................
.........................................................................................................
..................................
[1]
(ii) Explain how the orbit of a satellite can be made
geostationary.
.........................................................................................................
.........................................................................................................
[1]
(iii) What are satellites in geostationary orbits used for?
.........................................................................................................
.................
[1]
(b)
(i) What could satellite B be used for?
.........................................................................................................
.................
[1]
(ii) Briefly explain why its orbit makes it suitable for this purpose.
.........................................................................................................
.................
[1]
GCSE Examination Questions Mr Powell
1) Answer
(a) ideas that
(i) satellite stays in the same position relative to (any point on)
the Earth
1 mark
(ii) satellite must make one orbit in same time as Earth spins
once on its axis
1 mark
or
orbits at the same speed as the Earth rotates (do not allow
simply “same speed as Earth”) (credit satellite must be at
exactly the right height (and speed))
NB also credit the responses if given in (i)
(iii) communications / TV /telephone calls 3
1 mark
(b)
(i) monitoring/weather/spying (or similar) (not TV /
telecommunications) accept “for astronomy” for either (a) (iii) or
(b)(i)(but not both)
1 mark
(ii) idea that 2 (Earth spins under satellite so that) it can survey
all the Earth’s surface or low/close orbit so can see detail
1 mark
GCSE Examination Questions Mr Powell
2) H Describe, as fully as you can, the type of orbit into which a
weather observation satellite is put. (You may use a diagram as
part of your answer.)
Explain why this type of orbit is used.
.........................................................................................................
.........................................................................................................
.........................................................................................................
...................................................................................
3 marks
GCSE Examination Questions Mr Powell
2) Answers
§
§
§
§
polar orbit*
so observes different areas as Earth spins
low orbit
so can see more detail
or
§ so short orbit time / period [allow a figure if less than 4 hours]
N
[*credit
i.e assume
S
unless contradicted elsewhere in
answer]
any three for 1 mark each
GCSE Examination Questions Mr Powell
3) H The diagram shows the orbits of two satellites around the
Earth.
One of the satellites is used to photograph different parts of the
Earth. The other is geosynchronous.
(a)
(i) Give one use for geosynchronous satellites.
.........................................................................................................
.................
[1]
(ii) Explain which satellite is geosynchronous.
.........................................................................................................
.........................................................................................................
..................................
[1]
(iii) Draw on the diagram the direction in which the
geosynchronous satellite is moving.
[1]
GCSE Examination Questions Mr Powell
(b) The diameter of the Earth is 12 000 km, and the height of a
geosynchronous satellite is 35 000 km above the Earth’s surface.
The circumference of an orbit = 3.14 × the diameter of the orbit.
What is the speed of the geosynchronous satellite through
space?
.........................................................................................................
.........................................................................................................
........................................................
Speed = .................................... km/hr
[3]
(c) The satellite which is not geosynchronous continually
photographs a strip of Earth directly beneath it, about 200 km
wide. Explain why this satellite is able to photograph the whole
Earth in a matter of days.
.........................................................................................................
.........................................................................................................
........................................................
[2]
Total 8 marks
GCSE Examination Questions Mr Powell
3 Answer
(a) (i) any one from 1
radio (relay), credit a provider, phone (relay), tv (relay),
communications, navigation, weather (monitoring), credit spying
(ii) any one from 1
§
or
§
§
§
§
the equatorial or horizontal one
credit a label on the diagram
the one that goes east to west
is in furthest orbit from the Earth
because it moves around with the Earth's spin staying above
the same place
§ returns to the same place every 24 hours
§ orbits with the Earth every day
(iii) arrow at front pointing to right 1
(b) distance = (12,000 + 3x35,000) km × 3.14 1 = 257,480km
allow 257 000 or 257 610.6 or 258 000
time = 24 hrs or 1 day 1
speed = 10,728,1 km/h
allow range of 10 700 - 11 000
consequential marking allows two
marks to be awarded only if time is correct
(c) (the path is) over the poles
1 mark
the Earth is turning beneath (the orbit) 1 mark
[8 marks]
GCSE Examination Questions Mr Powell
4) Explain, in as much detail as you can, the importance of
gravity:
(a) in keeping a satellite in orbit around the Earth.
.........................................................................................................
.........................................................................................................
.........................................................................................................
.........................................................................................................
.........................................................................................................
[3]
(b) in enabling a star like the Sun to remain stable for several
billion years.
.........................................................................................................
.........................................................................................................
.........................................................................................................
...................................................................................
[2]
(c) for what might happen to the Universe in the distant future.
.........................................................................................................
.........................................................................................................
.........................................................................................................
.........................................................................................................
.........................................................................................................
......
[3]
[8]
GCSE Examination Questions Mr Powell
4) Answers
(a) idea that gravity
§ provides the force
§ centripetal/ towards the centre of the orbit
§ needed to produce the necessary change in direction/velocity
or to produce the necessary acceleration
§ to balance the speed
§ so continually falls around the Earth]
1 mark [3]
(b) ideas that
§ gravity holds the (matter of) the star together
§ gravity balances forces tending to make star expand/explode
§ these forces due to heat/temperature or nuclear/fusion
reactions
1 mark [2]
(c) ideas that
§ gravity slows expansion or changes KE to PE
§ •what eventually happens depends on size of gravitational
forces (compared to speed of expansion)
1 mark
§
if gravity not big enough Universe will expand forever [but
progressively less quickly]
1 mark
§ if gravity big enough Universe will stop expanding and
§ start to contract/there will be a big crunch
§ or “if there is enough matter” (in the Universe). [NB Answer
must relate the possible futures to the effect of gravity on
movement]
2 marks [max 3]
[8]
GCSE Examination Questions Mr Powell