Question 18
The locations of three space research sites in Australia are listed in the table.
| Site | Coordinates |
|---|---|
| A | 32° S 116° E |
| B | 32° S 136° E |
| C | 12° S 136° E |
Which site is closest to the equator?
[1 mark]Name the state or territory in which site A is located.
[1 mark]Determine and explain which two sites are in the same standard time zone.
[2 marks]Latitude answers part a), longitude answers part c)
Watch the three sites go on the map. Then follow a parallel for part a), the state border for part b), and the sun’s noon line sweeping west for part c).
Latitude says how far north or south. Longitude says what time the sun is overhead. The question is checking that you know which one each part needs.
Pick the pair, then the reason that earns the second mark
Answer part a), then choose a pair of sites and an explanation for part c). The map draws the line or distance your reason relies on, and the feedback tells you which marks your choice would earn.
Sites plotted from the table: A (32° S 116° E), B (32° S 136° E), C (12° S 136° E). A ring marks your part a) choice.
Part a): which latitude is nearest to 0°?
Part a): that’s it. 12° S is the smallest latitude, so site C is closest to the equator. Writing 12° S is also accepted.
Part c): choose a pair, then the reason. Which coordinate decides what time the sun is overhead?
Part c): now choose the explanation. “Determine and explain” is two marks, and the reason is the second one.
Part c): choose the pair as well. Naming the two sites is its own mark.
Three short answers and one reason
Try each step yourself before you reveal it. Parts a) and b) are one mark each. Part c) has a mark for the pair and a separate mark for the explanation.
Latitude is the angle north or south of the equator, so the smallest latitude is closest. Sites A and B are at 32° S and site C is at 12° S.
Site C
Answering “12° S” instead of naming the site is also accepted. Longitude plays no part here, so ignore the 116° E and 136° E.
Marker: correctly names the site
Find 116° E on the map. It is a little to the left of the 120° E meridian, and the whole of that strip is west of the dashed border at 129° E. Follow it down to 32° S, a little below the 30° S parallel, and you reach the south-west coast near Perth.
Western Australia
The abbreviation WA is also accepted. The map in the question doesn’t mark the sites, so this part checks that you can read coordinates against the grid.
Marker: correctly names the state
Time depends on longitude, so compare the longitudes in the table: 116° E, 136° E and 136° E. Two of them match.
Sites B and C are in the same standard time zone.
Sites A and B share a latitude, 32° S, which is the distractor. Latitude doesn’t affect the time.
Marker: correctly determines sites B and C are in the same standard time zone
“Explain” needs a reason written down, and the reason is the shared longitude.
Similar statements are accepted, such as “both sites are at 136° E”. In real life B is in South Australia and C is in the Northern Territory, and both use the same standard time, UTC +9:30, while Western Australia uses UTC +8. Real time zone borders follow state lines, so longitude explains the overall pattern, and it is the reasoning the marker wants. The word “standard” matters too: South Australia uses daylight saving and the Northern Territory doesn’t, so in summer their clocks differ.
Marker: correctly explains using longitude
Each phrase of the question gave you something
Reading coordinates from a table and locating them on a map is Unit 3 Earth geometry at its most direct, and there is no calculation at all. The 2023 subject report listed explaining which two sites share a standard time zone among the things students did well, and used part c) as a sample of effective practice: responses that named both sites and then explained why using longitude, in syllabus terms.
If I had to guess where you might lose marks, it would be part c). A and B share a latitude, 32° S, and the matching numbers make them look like a pair, but latitude says nothing about the clock. The other way to drop a mark is to write “B and C” and stop. “Determine and explain” is two marks, and the second one needs the reason: the shared longitude, 136° E.
Only mark this done when you could do it without help. Reading the solution does not count.
Question wording and marking-guide steps are from the 2023 QCAA General Mathematics external assessment, © State of Queensland (QCAA) 2023, licensed under CC BY 4.0, and have been adapted. Tangent Tuition is not affiliated with the QCAA.
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