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Refer to the orthophoto map - NSC Geography - Question 2 - 2019 - Paper 2
Question 2
Refer to the orthophoto map. 2.1.1 Calculate, in m², the average area of the Pongola aerodrome demarcated by 9 on the orthophoto map. Show ALL calculations. Marks w... show full transcript
Worked Solution & Example Answer:Refer to the orthophoto map - NSC Geography - Question 2 - 2019 - Paper 2
Step 1
2.1.1 Calculate, in m², the average area of the Pongola aerodrome demarcated by 9 on the orthophoto map.
Answer
To calculate the area, we use the formula:
From the orthophoto map, we find the dimensions:
- Length = 10.8 cm
- Breadth = 0.7 cm
First, convert these measurements from centimeters to meters:
Length (L) = 10.8 ext{ cm} × rac{100}{100} = 10.8 ext{ m} Breadth (B) = 0.7 ext{ cm} × rac{100}{100} = 0.7 ext{ m}Now, substitute these values into the area formula:
Thus, the average area of the Pongola aerodrome is 7.56 m².
Step 2
2.1.2 Why does the size of the Pongola aerodrome appear different on the topographic map in comparison to the orthophoto map?
Answer
The size of the Pongola aerodrome appears different on the topographic map due to the discrepancies in scale. The scale (1:50 000) on the topographic map makes the aerodrome appear smaller than it actually is, as it represents a larger area per unit measurement compared to the orthophoto map, which has a scale of 1:10 000. Additionally, the images may not align perfectly due to differences in resolution and perspective.
Step 3
2.2.1 Calculate the magnetic declination for 2019 using the information on the topographic map.
Answer
To calculate the magnetic declination for 2019, we start with the data provided:
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Difference in years: 17 years
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Mean annual change: 12' W (minutes)
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Total change:
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Magnetic declination for 2019: Given initial declination = 20° 0' + 3° 24' (204' converted to degrees) = 23° 30' W (minutes)
So, the magnetic declination for 2019 is 23° 30' W of true north.