There are many cases which successful execution depends on weather factors. In particular, from existence of wind and its force. It has significant effect for example on operation of high-rise construction and port cranes. The direction and wind force are surely considered by the sailors transporting cargoes across the oceans.
It is required to you
- - anemometer;
- - table ""Beaufort's scale""
Instruction
1. Figures are necessary exact here, and in this case for determination of wind force anemometers are used. To measure wind speed, come to the opened, blown place. Take the anemometer in an outstretched arm and expose it on wind. Take a stop watch in other hand. At the same time start a stop watch and release an anemometer brake. Cups will begin "to wind" meters, and you watch closely a stop watch meanwhile. After a minute, block the anemometer. Divide the received figures into 60, and you receive the average speed of wind vmetra in a second (m/s).
2. Measure wind force on external signs by eye: on a condition of trees, a grass; how flags flutter, linen on ropes; on whistle in ears and on force of overcoming a soprotivleniyavetr when you meet halfway. In use the wind on force is subdivided into 4 categories: – a light breeze – when leaves on trees and the thinnest branches constantly wave; – fresh wind extends panels of flags, whistles in ears; – such against which it is already difficult to go is considered strong wind, from it cable wires hoot; and, at last, – the gale can destroy fragile buildings, fells trees with a root.
3. More accurate gradation are offered by Beaufort's scale. It is a conditional scale for visual determination of wind force in points and approximate compliance of force of speed. It is called by name the English admiral Francis Beaufort who in 1806 developed a scale for application in the sea. Then the idea was spread around and processed, including for sushi. Take the table, find in the last column a line where the description of the actions made by wind is similar to the events at the time of observation. Determine force in points and the name of wind. In the subsequent two columns learn the approximate speed of wind in m/c¿ in km/h.