Tip 1: How to measure the width of a river
Tip 1: How to measure the width of a river
On a hike or a journey,the need to determine the distance to inaccessible objects, calculate the remaining path and measure the width of the river. To measure it, it is not necessary to dive into the water and swim the river, you can accomplish this task, guided by the rules of geometry.
Instructions
1
Find the river on the opposite bankan object located near the channel itself: a bush, a tree, a stone or a stump. Stand perpendicular to the flow opposite to this object. On the place where you stood up, drive a peg or insert a branch into the ground. Now move along the channel until an angle of 45 ° is formed between you and the object selected on the opposite shore.
2
To measure the angle, use the compass orwristwatch. Stand up so that the line running from 9 to 3 hours is parallel to the current, and the line from the center of the dial by 11 o'clock was 45 °. The distance you traveled from the peg is equal to the width of the river.
3
You can also determine the width of the river withblade of grass. Tear off the blade of grass. Choose two objects on the opposite shore and face them. Hands with a blade of grass extend forward and with her help measure the distance between objects, looking at them with one eye. Then fold the blade of grass twice and slowly move away from the river bank.
4
Stop when the folded blade of grass is notwill close the distance between objects. Insert a branch in this place, measure the distance you traveled from the bank of the river to the branch and translate it into meters. Got a distance that is equal to the width of the river.
5
Can be used to measure the width of a riverspecial pin maker. To make it, take a board and drive pins into it so that they form an isosceles rectangular triangle.
6
To measure on the oppositeSelect a subject from the river bank. Rise to the shore perpendicularly, after mentally drawing a line through the selected object. Drive along the river bank until the object and two pins are on the same straight line. The distance you have traveled is equal to the width of the river.
Tip 2: How to get width
The concept of width is applicable both to flat and to three-dimensional figures. Most often breadth such figures as a rectangle and a parallelepiped. For other figures, the concept of width is a reflection of its dimensions. For example, if we are talking about the width of the aircraft, then this may be the range of its wings. Similarly, the width of the folds of the relief or water bodies is measured, for example, the width of the river.
You will need
- - ruler;
- - topographic map;
- - calculator.
Instructions
1
To find breadth rectangle, measure the side that isis parallel to the observer's line of sight (leaves vertically). Conditionally, any side of a rectangle can be considered its width, then the adjacent side is called the length of this figure. Most often for breadth take the short side of the rectangle. With the known perimeter of the rectangle and its length, breadth calculate by yourself. To do this, divide the perimeter P by 2, and from the result obtained, subtract the length of the rectangle a (b = P / 2-a). If the area of this geometric figure S is known, its width will be equal to the ratio of the area to the length (b = S / a).
2
Another figure, for which the concept is appliedwidth - a parallelepiped. Its width is equal to the width of the rectangle that lies at the bottom. Therefore, in order to find this value for a parallelepiped, find breadth its foundation. Do this in the ways described in the previous step.
3
If the volume V, the length a and the height h of the parallelepiped are known, then find it breadth, successively dividing the volume by the length and height b = V / (a • h).
4
In order to measure breadth any other geometric figure orphysical body, find its longitudinal and transverse dimensions. One of them will be the length and the other width. For example, by measuring the longitudinal dimension of the car, get its length, and the transverse - breadth. The width of the aircraft is equal to the span of its wings, etc. The only exception is the circle, in which all dimensions are equal to its diameter.
5
To find breadth some part of the relief, for example, the river on a topographic map, find out its scale. Then, using the ruler, find this value on the map and multiply by the scale. Get breadth river in this place. For example, on a map with a scale of 1: 50000, the width of the river is 2 cm. Multiply 2 by 50,000 and get breadth rivers 2 • 50000 = 100000cm = 1km. The same technique is used to determine the width for any other object on the map.
