Question

Difficulty: HardMap Scale Conversion and Distance Calculation

A regional planning map with a statement scale of 2 cm to 5 km2\text{ cm to } 5\text{ km} is enlarged so that its linear dimensions are increased by a factor of 2.52.5. If the distance between two agricultural centers on the enlarged map measures 16 cm16\text{ cm}, what is the actual ground distance between them?

  1. A
    6.4 km6.4\text{ km}
  2. 16.0 km16.0\text{ km}Answer
  3. C
    40.0 km40.0\text{ km}
  4. D
    100.0 km100.0\text{ km}

Answer

The actual ground distance between the two agricultural centers is 16.0 km16.0\text{ km}.
The original statement scale of 2 cm to 5 km2\text{ cm to } 5\text{ km} simplifies to 1 cm to 2.5 km1\text{ cm to } 2.5\text{ km}. Enlarging the map's linear dimensions by a factor of 2.52.5 means that details become 2.52.5 times larger, so 1 cm1\text{ cm} on the new map represents 2.5 km2.5=1.0 km\frac{2.5\text{ km}}{2.5} = 1.0\text{ km}. Therefore, a measured distance of 16 cm16\text{ cm} on the enlarged map corresponds to 16 cm×1.0 km/cm=16.0 km16\text{ cm} \times 1.0\text{ km/cm} = 16.0\text{ km} on the ground.

Step-by-Step Solution

1
Determine the unit scale of the original map.
Since 2 cm2\text{ cm} represents 5 km5\text{ km}, 1 cm1\text{ cm} represents 5 km2=2.5 km\frac{5\text{ km}}{2} = 2.5\text{ km}.
Establishing the distance represented by 1 cm1\text{ cm} on the original map provides the baseline linear scale.
2
Calculate the new linear scale after map enlargement.
The new scale denominator is 2.5 km2.5=1.0 km\frac{2.5\text{ km}}{2.5} = 1.0\text{ km} per centimeter (1 cm to 1 km1\text{ cm to } 1\text{ km}).
Enlarging a map by a linear factor of 2.52.5 means each centimeter on the new map represents a smaller ground distance by a factor of 2.52.5.
3
Compute the actual ground distance using the enlarged map measurement.
\text{Ground Distance} = 16\text{ cm} \times 1.0\text{ km/cm} = 16.0\text{ km}.
Multiplying the measured distance on the enlarged map by the new ground equivalence yields the total actual distance.

Key Concept

Map Scale Conversion during Linear Enlargement
Estimated Time:2m 0s
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