"The Shape and Size of the Earth" PPT download

Description

"The Shape and Size of the Earth" PPT download

Part One: The Shape of the Earth

1. The earth is a sphere

2. The process of human understanding of the shape of the earth

The ancient Chinese theory of "a round sky and a square earth"

Aristotle speculated:

He was the first person to propose that the earth is spherical based on the phenomenon of lunar eclipses.

Activity

1. If the earth is flat, how do we see the process of ships appearing?

2. If the earth is a sphere, what is the process of seeing a ship appear? What do we see first? What do we see last?

3. Can you provide other evidence to prove that the earth is a sphere?

The Shape and Size of the Earth PPT, Part 2: The Size of the Earth

1. In what ways can the size of a sphere be expressed?

(Radius, perimeter, and surface area, etc.)

2. The shape of the earth is very irregular. (The difference between the highest mountain and the deepest ocean is nearly 20,000 meters.)

3. The northern and southern hemispheres of the earth are not symmetrical. (The North Pole radius is 40 kilometers longer than the South Pole radius.)

think

Comparing the equatorial radius and the polar radius, what new discoveries did you make about the shape of the Earth?

The difference between the equatorial radius and the polar radius is 21 kilometers.

Therefore, the earth is not a perfect sphere, but an irregular sphere with slightly flattened poles and slightly bulging equator.

The shape and size of the earth PPT, the third part: summary

1. The shape of the earth

1. The earth is a sphere.

2. The process of human understanding of the shape of the earth includes: "the sky is round and the earth is square"; Magellan successfully circumnavigated the world and successfully launched a manned spacecraft; humans witnessed the shape of the earth with their own eyes; photos taken by artificial satellites.

2. The size of the earth

1. The size of the Earth is usually expressed by data such as the Earth's radius, equatorial circumference, and surface area.

2. The shape of the earth is very irregular.

3. The northern and southern hemispheres of the earth are not symmetrical.

The shape and size of the earth PPT, part 4: Do it:

The navigator who first completed the circumnavigation of the world was ________;

The astronaut who saw the Earth for the first time was ________;

The average radius of the Earth is ________ kilometers, and the equatorial circumference is ________ kilometers;

The surface area of ​​the Earth is ________ square kilometers.

Keywords: Business Planet Edition seventh grade geography PPT courseware free download, the shape and size of the earth PPT courseware, .PPT format;

For more information about the "Shape and Size of the Earth" PPT courseware, please click on the "Shape and Size of the Earth" ppt tag.

"The Shape and Size of the Earth" PPT courseware download:

"The Shape and Size of the Earth" PPT courseware download

Part One Content: Learning a New Lesson

1. Introduction of new courses

The shape of the earth, as the name suggests, is "ball" shaped.

However, the understanding of the "spherical" shape has gone through a rather long process...

"The Shape and Size of the Earth" PPT courseware:

"The Shape and Size of the Earth" PPT courseware

Part One: The Shape of the Earth

What is the shape of the earth?

Many phenomena show that the earth is not as flat as intuitively. People imagine that the earth has been turned into an upside-down plate, and the sky is like a semicircular bucket...

"The Shape and Size of the Earth" PPT:

"Shape and Size of the Earth" PPT

Part One: The Shape of the Earth

One of the ideas of the ancients: the sky is round and the earth is round

What examples in life can prove that the ancients' views were wrong?

Evidence 1. The shadow of the Earth on the moon during a lunar eclipse

Gu Xi...

File Info

Update Time: 2024-10-05

This template belongs to Geography courseware Business Planet Edition 7th Grade Geography Volume 1 industry PPT template

Preview