I greet you, dear reader!
Somehow in my youth I was engaged in mountaineering and orienteering, and I do not know as of now, but at the time of need it was necessary to know the section, "Survival in extreme conditions" in order to pass the exam and get a discharge!
In fact, I decided to share with you and write this article brief, believing that it will be very informative and interesting! Actually ways even more than described here, but they are almost similar, and you While reading, penetrating the essence -'ll be able to simulate the situation and realize that everything is not so difficult.
Well, let's go...
Of course not often, but there are in our life situations and circumstances when it is necessary to know the height or distance of an object, such as houses, trees, yes or brag to his girlfriend))). You may need to build a path for the installation of a satellite dish, so that the signal "shoot" and avoiding high-rise buildings do not interfere with the crown of the trees... ))) And if that is not enough ...
Paradoxically, but not climbing with a tape measure on the subject - the calculation do not difficult, despite the fact that each method can give a fairly accurate result. Of course, with millimeter precision is not required to calculate the value, but the error is just too small.
The height of the drop shadow
If the weather is sunny and well-traced shadows, select the object on the lower reference point from which originates a drop shadow whether it's home, trees, poles, etc.
Further, we are looking for the end of the shadows and produce shadows froze length.
Then fix in an upright position any object (in the photo below - this is the usual peg) and similar measures the length of its shadow, and then another, and the height from the origin of the shadow of the object to the top.
I hope that you have no doubt that the photograph triangles with legs X1, Y1 and X2, Y2 are similar? The calculation is based on the geometric properties of similar triangles in which the relations between the parties are equal and the desired height of the object Y1 is as follows:
Y1 (column height) = (Y2 * X1) / X2
everyday items
This requires a move away from the object and using the materials at hand at arm's length (pen, pencil, stick) to measure the height. End object must coincide with the upper point of the object, and the lowest point is required to fix the thumb.
Expand the object horizontally so that the bottom of it was still the object of a base and the tip touched the ground and pointed to a certain point. It is important to remember this point, or if there is an assistant asked to stand on this point. Just this point will be the point of projection of the top to the ground and now remains only to measure the distance.
The angle of incidence and angle of reflection
And if there is no sun and the rain, too, does not matter!
According to the law of refraction of physics, that the angle of incidence equals angle of reflection - mirrored any puddles you can find the top of the object and knowing your height and distance, respectively - to get the desired height (see figure below).
Secure point O with any object, thrown into the puddle. This way you can measure the distance OA, OA1.
Knowing all the necessary values, and based on the properties of similar triangles, you get high, which will be equal to:
AB = (A1B1 * OA) / OA1
Barometer and a bit of humor
We will need a little knowledge of physics. From the school course we know that the atmospheric pressure depends on the height above sea level, and measuring the pressure at the bottom of the object and on the top - it is possible to calculate the ascent distance.
The average value of the atmospheric pressure reduction is 1 mm. Hg. column for every 12 m in height or 133.32 Pa (Pascal), which is -. same. Therefore, no matter what units received pressure - you can always count high. And if you have a stop watch (it is in every phone), then reset the barometer with height, and the timing with his fall)))))).
The path traversed by the body in free fall is equal to:
S = (g * t ^ 2) / 2, wherein:
g - acceleration of gravity - 9.8 m / s ^ 2;.
t - time stopwatch with.
Determine the height of the object at a distance from you
To determine the height of us in any case required distance to the object, but the base of it, we is not available - in this dimension can not be done directly.
To calculate the distance, we need to:
- Stop in front of the object, and fix this point (Figure point A).
- Turn at a right angle (90 deg.), And take a few steps. This point will be the point O (here it is necessary to stick a long object such as a stick).
- Travel the same distance as that from A to G, and in the same direction. Mark any item (point B).
- Turn at a right angle (90 deg.) And removed from the object (towards point Y) as long as your item is set at the point O will not be aligned with the object.
- The distance from your (Y) to point B - this is the distance from the point A to the object (X).
Now, knowing the distance to the object, we proceed to the calculation of its height.
For simplicity of construction, again similar triangles - taken pole with a travel bar (two nail boards slipping). The device is fixed at the point A, the bar is adjusted (using congenital eye estimation in every one of us) at the top of the object point (X 1) - as shown in the illustration, and then fixed.
Further, there is a point on the ground S.
As a result, we get two triangles SKHH1 and Caa1, which are similar to each other. Knowing cholesterol distance, AU and AA1 find the required height H of the object!
Height H = (AA1 * CH) / AC.
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1. If the diagonals are equal, it does not mean that you have a steady home. Why? I tell the story!
2. Why is the main size of metal products is in the length of 11.7 m.?
3. Variants of construction of right angles in the construction of the house and check the angles at the already erected.