§ 11. Scale (textbook)

§ 11. Scale


Concept on a scale.The distances on the ground pointing in meters or kilometers. For example, the distance from your home to school distance of 400 m. This paper can not be displayed. Therefore, plans or maps the distance given in a reduced size - in inches and millimeters. To convert large distances in small areas on the plan, use the scale.

Scale - A measure of reduce distances in areas of the picture on the plan or map. In other words, the scale indicates how many times in the distance on the ground reduced to paper.

What larger scale, the greater the reduction. The larger reduction in the more its area can be represented. But the more reduction, the smaller and become less distinct objects on the plan or map. Thus, the larger the scale, so it is smaller.

Types scale.The scale can be written as fractional numbers, such as - 1: 10 000. Scale, expressed as fraction, called numerical. Number 1 (numerator) - is the distance on the plan, which corresponds to 10 000 (Denominator) of such distances on the ground (ie, 1 cm on the plan = 10 000 cm areas). In the numerical scale, in the numerator is always unity. And the denominator can be any number that shows how many times the distance in terms of lower than on the ground. It is important to remember that the numerical scale of both figures always given in inches. For convenient numerical scale to determine how much times the short distance on the plan.

Often along with a numerical scale write his explanation. For example, in 1 100 m sm (10 000 cm for easy transfer in meters). This also means that one centimeter on the plan meets the 100 meters on the ground. Scale, recorded  words, called named. Distance on the ground, which corresponds to 1 cm on the plan called the largest scale. With the magnitude scale is more convenient to define distance. For example, as long as the school garden, if its length on the plan - 3 cm and the size scale - 100 m? It is easy to calculate that the garden has a length of 300 m (3 x 100 m = 300 m).

As convert a numeric scale for named? Let there be a numerical scale 1: 25 000. To rename it will transfer 25 000 cm in feet (25 000 cm = 250 m). Thus, named scale - 1 cm in 250 meters

On plans also contain linear scale. It portrayed as a straight line, which is divided into equal parts (usually centimeters). Near the point value of each line nadpysuyut Accordingly, scale, distance on the ground (100, 200, 300 m ...). At the same zero set, departing at 1 cm from the left edge segment. A first centimeter divided into millimeters (which mean respectively 10, 20, 30 m. .. on the ground). By using the linear scale can quickly and easily measure distances and determine sizes of objects in terms of using the compass-meter.

Measurement distances on the plan.The distance between two objects on the plan in a straight line measured normal ruler. You can also use a compass-meter. To do this, placing the arm at the extreme point of the segment being measured (eg, from village to station). Then, without changing the position of the legs compasses, put it on the line scale. Signs on the line immediately will say what is the distance to the terrain. If compasses swing legs does not match a whole number of centimeters on a linear scale, the compass displace left behind the line so his right leg was on the whole podiltsi. Then will be seen not only centimeters, but the number of millimeters in the band, which specify the distance.

Sometimes that the plan or map, not a direct measure distance and distance in in broken, curved lines (eg, long meandering stream). Then we can use regular thread. Threads to put a curve on the plan, repeating her curves. Then, vypryamyvshy thread  measure its length ruler.


Questions and Tasks

1. What is scale?

2. Determine how many times the distance of the plans reduced to a numeric scale: a) 1: 200;  b) 1: 2 000 c) 1: 20 000. Which of these scales to the highest reduction?

3. What will be the distance of 60 m on plan, if the scale - 1 cm in 10 meters?

4. Create the image in notebook distance of 500 m in scale: 1 cm to 100 m, 1 cm in 250 m. What of magnitude smaller?