Chapter 2: Map scale
Items needed to complete this lab:
■ Ruler, see printable ruler link if you do not have one.
■ Hand calculator or calculator program on your PC
■ Tables in appendix C of Map Use book
Key distance conversions
Conversions between different units of measurement are also an important part of scale and distance calculations. Key conversions are listed below:
■ 1 inch = 2.54 centimeters
■ 1 statute mile = 5,280 feet = 63,360 inches
■ 1 statute mile = 1.609 kilometers
■ 1 kilometer = 100,000 centimeters
■ 1 nautical mile = 6,076.1 feet
■ 1 foot = 12 inches
■ 1 meter = 100 centimeters
Explanation of representative fraction
Map scale is defined as the mathematical relationship between a unit of distance on the map and its corresponding distance on the ground. The ratio of map distance to ground distance, both in the same units of measurement, is called the representative fraction (RF) for the map. It is computed from the following equation:
1/X = map distance (md) / ground distance (gd)
We will use this equation in the following scale problems. Hence, an RF of 1/24,000 means that 1 centimeter on the map represents 24,000 centimeters on the ground, 1 inch on the map represents 24,000 inches on the ground, and so on for other units of distance measurement. The RF can also be written as 1:24,000.
Map Scale Questions
1. Convert the following representative fractions into a word statement. (Enter number for x only, no units)
Express the scale of a large-scale map with an RF of 1:50,000 (1 inch to x feet) (whole number)
4166 inch .
Do the same for a medium-scale map with an RF of 1:250,000 (1 inch to x statute miles) (2 Decimal places)
4mile .
And for a small-scale map with an RF of 1:100,000,000 (1 inch to x statute miles) (Whole number)...