# Lesson Planning of Shape of the Earth

Lesson Planning of Shape of the Earth & its Spin Motion

Subject General Science

Students` Learning Outcomes

• After studying this lesson, the student will be able to:
1. Describe the shape of the earth.
2. Relate the earth`s spin with the occurrence of day and night.

Science Process Skills

Observing, Communicating, Inferring, Predicting, Experimenting, Making and using models

• The students have learned the following concepts in the previous lesson:

Ø  Heat and light of the sun help to sustain life on earth.

Ø  Sun rises in the east and sets in the west.

Information for Teachers

• Our earth is not flat. It is round in shape. It is a big sphere like football. As a small piece of large sphere looks flat; similarly, the earth appears to us as flat because we can see only a small part at a time. During space exploration, scientists observed with their own eyes that the earth is round like a sphere.

• Do you know?
• In the early sixteenth century a Spanish ship returned to Spain after taking a round trip of the world. This trip proved that the earth is round.
• More proof of the earth`s being sphere is provided by a ship approaching the sea shore. When the ship is far away, only the mast (a tall flag pole) of the ship is initially seen.
• The lower part of the ship appears later when the ship gets closer to the shore. If the earth was flat, all parts of the ship would appear at the same time.

Material / Resources

Writing board, chalk / marker, duster, a football and a ball-point pen, a globe, a torch, knitting needle, a ball of wool or an orange

Introduction

1. What do you think is the shape of the earth?
2. How do you know this?

• Show them a football and ask them:
• If a small ant lived on this ball what would it think the shape of the ball is?

Development

Activity 1

Material required

A football and a ball-point pen

• Methods:

1.      Give each group a football and mark on its surface a small area with a ballpoint pen.

2.      Students observe the marked area or feel it by moving their fingers over it. Does it appear flat?

Demonstration

• Show the photograph of the Earth taken from space and ask students to comment on the photograph.
1. Hat is the shape of the earth?

Activity 2

Material required

A globe

• Divide the class into groups of 5 and provide each group with a globe turn by turn.

1.      Ask whether we can make a round trip of the earth?

2.      Starting from some point on the globe, trace the path along which we can come back to the same point after making a round trip of the world.

3.      Children write the name of the way of the round trip.

4.      Would it be possible to take a round trip if the earth was flat?

Key point: The earth is spherical in shape.

Spin of the earth

Background information

• The sun rises in the east and sets in the west. The early people believed that the sun was orbiting the earth. Now, we know that this is not true. The earth goes around the sun. this is called rotation of the earth. Then, how do day and night appear? Scientists explored that in addition to the rotation of earth around the sun, the earth also spins on its own axis like a top. The axis is an imaginary line that passes through north and south poles of the earth. The days and nights are caused by the spin of the earth. The side of the earth that faces the sun has day and the side that faces away from the sun has night. The earth completes one spin in 24 hours.

Activity 3

Material required

A torch or lamp, knitting needle, a ball of wool or an orange

• Methods:
• Divide the class into suitable groups and direct them to follow the given instructions:

1.      Switch on a torch or a lamp in a dark room.

2.      Push a knitting needle through the ball of wool and spin it in front of lamp.

3.      Observe which part of the ball is bright and which pat is in darkness.

• Ask: if the lamp is the sun and ball of the wool is the earth, which part of the earth will have day time and which part night time?

Activity 4

Material required

A globe and a torch

• Methods:
• Divide the class into groups of 5-6 each and ask them to follow the given instruction:

1.      Place a globe on a table in a dark room. Note that the axis of globe is tilted.

2.      Throw light from a torch on the globe while slowly rotating it.

3.      Is the whole surface of the globe bright or only one half of the globe?

4.      Is the other half dark?

Activity 5

• The earth turns around once every twenty four hours as shown in the figure given below. Show the students the following picture or draw it on the board. Ask the children to observe carefully and answer the following questions:

1.      Which places (Mark letters) are in day light in this picture? _________.

2.      Which places are in night? ___________________________________.

3.      Which place is going from night into day?  ______________________.

4.      The earth spins on it`s axis. What do we call the ends of this axis? ____.

Sum up / Conclusion

• Just like the torch the sun also brightens the earth. Wind up the discussion by concluding:

Ø  One half of the earth is lit by the sun while the other half is dark.

Ø  There is day at the bright part of the earth and night at the dark part.

Ø  Since the earth completes one rotation one its axis in 24 hours, the total duration of one day and one night is 24 hours.

Ø  The earth spins on its axis which causes day and night.

Ø  As the spin of the earth is directed from west to east, so the sun, moon and stars appear to move from east to west in the sky.

Assessment

1.       Fill in the blanks.

i.                     Our earth is ________ in shape.

ii.                   Day and night appear due to _________ of earth.

2.       Match column A and B

 A B i.                  Spin of the earth ii.              Shape of the earth i.                   Spherical ii.                Day & Night

3.       How do the day and night appear?