Rotation and Revolution

1. Unit-01
Studying the
Earth

2. 2. Movements of
the Earth

5. The Earth rotates
on it’s own axis.
It’s axis is an
imaginary line that
passes through the
North poles and the
South poles.
This axis is tilted
at an angle of 23.50

6. The Earth takes
24 hours to
complete one
rotation about its
axis. This is called
One Earth-day
The Earth travels
2,200 km per hours.

8. The Rotate of the Earth causes Day
and Night.
As the Earth rotates on its axis, half
of the earth faces the sun and half of the
earth faces away from the sun.
The half of the Earth that faces the
sun will experience Day.
 While the half of the Earth that faces
away from the sun will experience
Night.

10. The period
between Night
and Day is called
Dawn.
The period
between Day and
Night is called
Dusk.

11. REVOLUTION

12.  The Earth revolves around the Sun is called Revolution.
 The Earth revolves around the sun in fixed path and it is
called orbit.
 The Earth’s orbit is Elliptical or Oval shape.
 The Earth takes 365 days and 6 hours to complete one
revolution.
 The speed of Earth’s revolution is about 18 miles per
hour.

13. The Earth, takes 365 days and 6
hours, to complete one revolution.
The extra 6 hours accumulate over
four years and are added as a day to
the month of February every fourth
year.
So February, which usually has 28
days, has 29 days every fourth year.
This year is called a “ Leap Year”
and has 366 days.

14. The Effects of the
Revolution of the Earth:

15. Most places on Earth experiences different seasons
in a year.
THREE FACTORS CAUSES THE
SEASON:
The revolution of the Earth around the Sun.
The tilt of the Earth’s axis of Rotation.
The tilt’s of the Earth axis remain constant.

16. The Earth experience different seasons in a year,
namely
 Summer,
Winter,
Spring,
Autumn.

17. In March ,neither of the poles is
facing the sun. It is the Spring in
the Northern Hemisphere, and
Autumn in the Southern
Hemisphere.
In June, the North pole is
facing the Sun, While the
south pole is facing away
from it. So it is Summer in
the Northern Hemisphere,
and Winter in the Southern
Hemisphere.
In September, neither of
the poles is facing the
Sun. It is Spring in the
Southern Hemisphere
and Autumn in the
Northern Hemisphere.
In December, the South pole is
facing the Sun, While the North
pole is facing away from it. So
it is Summer in the southern
Hemisphere and Winter in the
Northern Hemisphere.

18. The part of the Earth that is tilted
towards the sun gets the directs rays of
the Sun and has Summer, While the
part that faces away from the Sun,
receives less heat from the Sun, and so,
has Winter.
 Twice a year, in March and September,
neither of the poles is facing the Sun, and
all parts of the Earth get roughly equal
hours of daylight and darkness.

19. At this time, Places on Earth have
seasons like Autumn and Spring,
Which are neither too hot nor too cold.
The Northern Hemisphere and the
Southern Hemisphere experiences
opposite seasons.
FOR EXAMPLE: In December,
Canada, which lies in the Northern
Hemisphere, has Winter. While
Australia in the Southern Hemisphere
has Summer.
 In June, Canada experience Summer,
while Australia experience Winter.

21. The Summer months are hot
and dry. The days are long and
nights are short. In many
places river and lakes run dry.

22. In Autumn, leaves change colour and
start falling from the tees. Days and
Nights are of the same length. The
weather is Pleasant.

23. It is very cold during Winter. In
many places Snow falls. Trees
lose all their leaves. The Days are
short and the Nights are long.

24. During spring, Trees Sprout new leaves
and Flowers bloom after the cold
winter months. Birds build nests. The
Weather is mild and pleasant.

25. MONTH NORTHERN
HEMISPHERE
SOUTHERN
HEMISPHERE
MARCH SPRING AUTUMN
JUNE SUMMER WINTER
SEPTEMBER AUTUMN SPRING
DECEMBER WINTER SUMMER

26.  In India, we have yet another season- the
MONSOON.
 This is the season of rains in India. It occurs
every year between June and August.