scsvshsstclass5e(08.5)

ROTATION AND REVOLUTION   (Part 5)

May 8,2020

Are we all set for the class? Okayy !

A very good morning to you boys!

In the previous class, you have understood the concepts of how seasons are caused and

why June 21st is the longest day in the northern hemisphere.

It means that what we will be learning today ,is the continuation of how seasons are caused.

On completion of the topic, you will be able to:

# explain why there are different seasons in different regions of the world

# define solstices; summer & winter

# know the difference between the two solstice

# explain the significance of winter solstice

You have learnt that when the northern hemisphere lean towards the Sun, it receives more sunrays.

Whereas, the southern hemisphere leans away from the Sun, receiving less sunrays.

Therefore, 21st June is the longest day in the northern hemisphere

 which marks the SUMMER SOLSTICE. 

Similarly, the northern hemisphere leans away from the Sun and the southern hemisphere 

leans towards the Sun.

Now what happens is, that, the northern hemisphere receivs less sunrays and have winter season.

Therefore, 22nd December is the shortest day in northern hemisphere 

which marks the WINTER SOLSTICE.

Watch this video which tells you what happens during the winter solstice.

SOLSTICES OCCUR WHEN THE SUN IS DIRECTLY OVERHEAD THE TROPICS.

There is one more interesting thing which occurs during the entire revolution of the earth.

Have you heard about Equinox?

When the Sun shines twice directly over the Equator, it is called Equinox.

The interesting fact about Equinox is ,that,the length of day and night are equal.

The equinoxes occur on 21st March and 22nd September.

Another interesting fact:

An exception to the above cases is the North Pole and the South Pole.

These regions receive sunrays for six months alternatively, meaning:

a six-month duration of day, which means, half a year is summer,

a six-month duration of night, which means, half a year is winter. 

I think ,today , we have learnt some interesting facts about Earth and its movements:

occuring of solstices ,equinox and the reason of six-month duration of day and night at the two poles.

H.W. Read the entire lesson again so that you fully understand about Movements of the Earth.

We will be doing Q's.and Ans. tomorrow. So, be ready with your notebooks.

ENJOY READING !