[Physics Class Notes] on Wind Vane Pdf for Exam

A wind vane is an instrument that helps to show the direction of the wind. It is a common sight on buildings, especially at the highest point of the building. The word “vane” actually comes from “fana,” which means flag. A wind vane is highly functional but is also used for decorative purposes nowadays. Some common motifs which are used for wind vanes are ships, arrows, horses, and cockerels. The direction which the motif faces is generally the direction from which the wind is blowing. 

The first wind vane was recorded in 48 BC by Greek astronomer Andronicus. The motif on the wind vane was of Triton (the Greek god of the sea) with a wand, which indicated the wind direction. Nowadays, there are many kinds of wind vanes. The world’s most giant functional wind vane can be found in Montague, Michigan. It measures 48 feet (14.6 meters ) tall with an arrow measuring 26 feet (7.9 meters) long. It has a traditional arrow shape with a ship on top.

Wind Vane Working Principle

The critical principle responsible for the working of wind vane is that its design and construction should allow unrestricted movement of the wind. This means that there should be free movement of wind, especially around the vertical axis of the structure. 

Another critical factor to keep in mind is that the construction works best when the design is not symmetrical. This is required so that the lighter and smaller area can face the direction that the wind is coming from. Although the shape can be unequal, the weight has to be equal on both sides of the structure’s vertical axis. The wind vane rotates on the axis, and it also allows it to spin freely.

 

It is crucial that the directions – north, south, east and west, are marked on the wind vane. This allows us to read the wind vane accurately, even from a distance. 

Another factor that affects the wind vane’s working is the height at which it is installed. It should ideally be installed at the highest point of the building. This prevents any other tall structure of building from manipulating the wind’s direction and affecting the wind vane’s reading. Observing and following a wind vane’s model accurately makes it easier for us to understand how it works.

How to Make a Wind Vane?

There are lots of different ways in which you can make a wind vane. This is also a great science experiment.

Things you will need:

• Thick paper

• A pair of Scissors

Method:

Using a ruler, cut a triangle that can be a pointer for the wind vane. This should be approximately 4 cm at the base, and 5 cm tall. Next, draw a square that is about 7 cm on each side. Now, the square and the triangle are the two sides of your wind vane. 

Once you have both the pointers ready, cut evenly measured slits on both sides of the drinking straw. It is best to keep the lengths identical but not necessary. These slits should be approximately 1 cm in length. Once the slits are made, open the straw up at the top and stick the triangle on one side and the square on the other side. Your structure should look like an arrow. 

Now insert a pin in the centre of the straw and attach it to the eraser on the top of the pencil. This should be stable for a well-made wind vane. The other end of the pencil that we usually use to write will go into a block of clay, so that it remains stable. Roll the clay into a ball first, and then put the pencil in. 

For the base of the wind vane, copy a compass and mark east, west, north, and south on it. Push the clay and stick it in the middle of this compass like base. Your wind vane should look like the picture shown below. To keep it still and stable, you can attach this structure to another heavy object like a can with stones or sand in it.