# Lesson Notes By Weeks and Term - Senior Secondary 1

The Earth

TERM – 1ST TERM

WEEK THREE

Class: Senior Secondary School 1

Age: 15 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Geography

Topic: THE EARTH

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Describe the shape and size of the earth.
2. Argue the proofs of earth’s spherical shape.
3. Differentiate between earth’s rotation and revolution.
4. Appraise the impacts of earth’s rotation and revolution on man and his environment.

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers,

demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

 PRESENTATION TEACHER’S ACTIVITY STUDENT’S ACTIVITY STEP 1 INTRODUCTION The teacher describe the shape and size of the earth. Students as a whole class, discuss the shape and size of  the earth STEP 2 EXPLANATION Teacher explain the proofs of the Earth's sphericity. Students in pairs prove why the shape of the earth is spherical and state the difference between rotation and revolution STEP 3 DEMONSTRATIO N Teacher differentiate the Earth's rotation and revolution and it's impacts to Man and the environment Students in small groups highlight the effects of earth’s rotation and revolution and appraise their impacts on man and his environment STEP 4 NOTE TAKING The teacher writes a summarized note on the board The students copy the note in their books

NOTE

THE EARTH

Size and shape of the Earth

Earth is the third planet from the Sun in our solar system and is the only known celestial body to support life. It has a diverse environment with oceans, continents, and an atmosphere that sustains various forms of life.

The Earth is an oblate spheroid, meaning it's mostly spherical but slightly flattened at the poles and bulging at the equator. Its average diameter is about 12,742 kilometers (7,918 miles).

Proofs for Earth's spherical shape

There are several pieces of evidence that support the Earth's spherical shape:

1. Circumnavigation: When ships or aircraft travel around the Earth, they eventually return to their starting point, indicating a spherical surface.Ferdinand Magellan and his crew sailed round the world between 1519 and 1522 and came back to their starting point. Since then, several other people have done so thereby confirming the fact that the earth is not flat but spherical
2. Sunrise and Sunset: Different parts of the world experience sunrise and sunset at different times. If the earth were flat, the sun would rise and set at the same time for all places.
3. Shadow during a lunar eclipse: The Earth casts a round shadow on the Moon during a lunar eclipse, providing a circular evidence of its shape.
4. Satellite images: Photos taken from space clearly show the Earth as a spherical object.
5. Ship’s Visibility: When a ship approaching a port is viewed, the top of the mast is seen first before the hull and later the rest of the ship’s body. In the same way, if a ship leaves a harbour, it disappears gradually. If the earth is flat, the ship from a distant view would appear and disappear at once.
6. Shape of other Planets/Planetary Bodies: When the sun, moon, stars and other planetary bodies are viewed from any angle, they are all circular in outline. So the earth cannot be an exception

Differences between earth rotation and revolution

Earth rotation and revolution refer to distinct motions

 Aspects Earth rotation Earth revolution Motion Spinning on its axis Orbiting around the Sun Axis Imaginary line through North and South Poles Elliptical path around the Sun Duration Approximately 24 hours for one complete rotation Approximately 365.25 days for one complete orbit Effects Causes day and night cycles Determines changing seasons as Earth orbits the Sun.

Impacts of Earth's rotation and revolution to Man and his environment

The rotation and revolution of Earth have significant impacts on both humanity and the environment:

Rotation:

1. Day and Night: Earth's rotation creates day and night cycles, influencing daily activities and sleep patterns for living organisms.
2. Coriolis Effect: The rotation generates the Coriolis effect, influencing global wind patterns and ocean currents, impacting climate and weather.
3. Gravitational Force: The rotation contributes to the Earth's gravitational force, affecting weight and mass measurements.

Revolution:

1. Seasons: Earth's revolution around the Sun causes the changing seasons, influencing temperature, weather patterns, and agricultural cycles.
2. Tilted Axis Impact: The axial tilt combined with revolution leads to variations in sunlight intensity at different latitudes, affecting climate and ecosystems.
3. Calendar System: The year is defined by Earth's revolution, forming the basis for our calendar system and various cultural celebrations.
4. Agriculture: The changing seasons due to revolution impact crop growth cycles and agricultural practices.

EVALUATION: 1. Describe the shape and size of the earth.

1. Discuss the evidence that proves that earth is spherical
2. Differentiate between earth rotation and revolution
3. Mention 2 impacts each of Earth's rotation and revolution

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively