Answer the ff. questions:

Post by **answerhappygod** » Thu Feb 17, 2022 11:05 am

: Answer The Ff Questions 1 (86.86 KiB) Viewed 142 times

33 8 Highlight A. Instruments & Accessories: Triangles, Graduated Straight Edge, Pen, Pencil, and other Drawing Instruments B. Procedure: 1. This problem is an indoor lab exercise which highlights a type of office/drafting work related to most surveying and mapping operations - the design and construction of graphic (or bar) scales. 2. The lab instructor has the option to use the prepared data, revise it or give a new set of data. 3. The following illustrative problem is given to enable the student to understand the process involved in designing and constructing graphic scales: It is desired to construct a graphic scale for a map with a given fractional scale of 1:25,000. Design the graphic scale to make readings 1,000 m units. Portray a total length of 3,00 m on the primary scale and 1,000 m on the extension scale which must be subdivided into 10 smaller graduations. a. Since 1.000 m equals 100.000 cm, the problem can thus be stated as follows: "Since 1 cm on the map represents 25,000 cm on the ground, then how many centimeters on the map will it take to represent 100,000 cm on the ground?" b. The solution can be worked out as a problem in ratio and proportion, as follows: 100,000 1:25,000 = x: 100,000 or x = or 4 cm 25,000 c. We have now determined that 4 cm on a map of scale 1:25,000 represent 100,000 cm (or 1,000 m) on the ground. We now proceed as shown in the accompanying figures. d. Draw a line 16 cm long and mark off four 4 cm divisions. This line represents an equivalent of 4,000 m on the ground. From the leftmost end of the line (a). draw another line at an angle of 45 degrees (the angle may be anywhere from 30 to 60 degrees) long enough so that it can easily be divided into ten equal parts. e. With a ruler or divider, lay off on this line 10 equal parts and then draw a line which will connect the 10th part with the index point (b). Draw lines parallel to this line through each division and let each line divide the previously drawn line (ab). The parallel lines will divide the 4 cm long line (ab) into ten equal parts where each part is equivalent to 100 meters. 1. The desired graphic scale as shown in the lower figure is completed by labeling the extension and primary scales, and drawing two closely spaced parallel lines with shaded alternating segments.

ment A random line drawn of an angle (preferably between 30 and 800) and subdivided into 10 equal porta 4cm. 4em. 4cm 4 cm Extension Scale Primary Scale (12 cm) g. 5-11. The coupleted graphic scale. Index Point NOOO 500 1000 2000 3000 Extension Soals Primary Scale SCALE 120,000 4. Listed below are four different fractional scales (metric) for topographic maps. You are required to design and construct equivalent graphic scales according to specifications prescribed for each. The graphic scales must be designed to enable the map user to measure specified linear units on the map using either the primary or extension scales.

a. Fractional scale - 1:1,000,000 Primary Scale unit = 50 km Total length to be portrayed on primary scale foo km Length to be portrayed on extension scale = 50 km Number of subdivisions on extension scale - 5 b. Fractional scale = 1:250.000 Primary scale unit - 10 km Total length to be portrayed on primary scale = 30 km Length to be portrayed on extension scale = 10 km Number of subdivisions on extension line = 10 c. Fractional scale = 1:100,000 Primary scale unit - 5,000 m Total length to be portrayed on primary scale = 15,000 m Number of subdivisions on extension scale = 5 d. Fractional scale = 1:50,000 Primary scale unit = 1 km Total length to be portrayed on primary scale - 5 km Number of subdivisions on extension scale - 5 c. Con tations: The computation illustrated in the procedure, item 3(b), may also be expressed by the following formula MD RF = or MD = GD(RF) GD Where RF = representative fraction (1/25,000) or fractional scale MD = map distance (the unknown quantity or the distance on the map which will represent 1,000 m) GD = ground distance (1,000 m or 100,000 cm) D. Remarks, Hints & Precautions: 1. The scale of a map is defined as the ratio between distance as it is represented on the map and as it is measured horizontally on the ground. 2. A representative fraction shows one type unit on the map equal to a certain number of equal type units on the ground. The unit of distance on both sides of the ratio must be the same.

3. A graphic or bar scale is a line subdivided into map distances corresponding to convenient units of length on the ground. Graphic scales are drawn with at least 3 whole units to the right of the index mark. The units begin at zero with an extension to the left of zero to serve as a convenience for users who have to figure out shorter distances which are fractions of the unit. 4. On a map two or more graphic scales are sometimes drawn to allow the use of different units of measurement. The scales are generally shown in meters and feet or kilometers and miles. 5. The index point of graphic scales should be lined up under one another when two or more units are represented in a map. This will allow easy and quick comparisons between ground distances in the different units. 6. Four different graphic scales will be submitted by each student, and each must be drawn accurately to the specified scale. 7. All drawings should be made on 8.5" by 11" paper with the prescribed specifications and accompanying computations indicated. It must also be completely labeled and each prepared graphic scale should be accompanied by another figure which will show construction lines and related measurements made. 8. As a variation to the requirements stated in this lab exercise, the students may be asked to design and construct equivalent graphic scales in the English system or they may be required to design and construct graphic scales in both the English and metric systems.