Page 194 - New Medley 3 Semester 2

What Makes the Earth a Livable Planet

e Earth has water and air on it. It gets light and heat from the sun. ese are

the basic needs of life. e presence of air, water and sunlight makes life possible
on the Earth.

MOVEMENTS OF THE EARTH

e Earth is not stationary. It is moving continuously. It
shows two di erent types of movements. It rotates on its

own axis just like a top. is is called rotation of the Earth.

It also moves around the sun on a xed path. is path is

called orbit. e movement of the Earth around the sun is

called a revolution.

Axis Rotation The Earth
Pole
e Earth completes one rotation in 24 hours that

equals one day and one night. When the Earth rotates

on its axis, half of it faces the sun. e part facing

the sun has daytime. e other half that does not
face it and is away from the sun has night. When
Pole it is daytime in India, it is night in America. It is

Rotation of the Earth on its axis so because these two countries are on the opposite
sides of the Earth. us, rotation of the Earth causes

day and night.
• Hands-on Learning
Activity S E L Self-Management

Take a table lamp and consider it as Sun. Place it on a
table in front of a globe. Focus it on the globe. Note the
part of the globe getting light represents the day and
the opposite side is night. Now, slowly rotate the globe
and observe what happens.

Revolution Knowledge Zone

e Earth completes one revolution in 365 The Earth is about 4.56 billion

days and 6 hours. is time period is called years old.

192