"Shape and Size of the Earth" PPT

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"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

The ancient Greek scientist Aristotle (384 BC - 322 BC) observed a lunar eclipse and discovered that the shadow of the earth on the moon was an arc, thus inferring that the earth is actually a sphere.

Evidence 2. When looking at ships approaching from a distance on the seashore, you always see the mast of the ship first, and then the hull.

Evidence 3: The higher you climb and look into the distance, the larger the horizon you see.

The shape and size of the earth PPT, part 2: think about it

1. If the earth is round, will people on the other side of the earth fall?

2. If the earth is round and you keep moving forward, will you eventually return to where you started?

3. Since the earth we live on is a sphere, why do we see flat land?

Reason: What we can directly see is only a very small area of ​​the earth's surface, so it is difficult to perceive the earth's curved surface.

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

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

Make a note

Polar radius: 6357km

Average radius: 6371km

Equatorial radius: 6378km

Equator circumference: about 40,000 km

Surface area: 510 million square kilometers

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

1. After calculation, the average radius of the earth is ( )

A. 6357 kilometers B. 6371 kilometers

C. 6378 kilometers D. 6367 kilometers

2. Among the following four descriptions of the shape of the earth, the one that is more realistic is ( )

A. An irregular sphere that is slightly flattened at the equator and slightly bulging at the poles;

B. An irregular sphere that is slightly flattened at the poles and slightly bulging at the equator;

C. An irregular sphere with a polar radius slightly longer than the equatorial radius;

D. An irregular sphere whose equatorial radius is much longer than its polar radius;

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"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 download:

"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:

According to the lunar eclipse...

"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...

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Update Time: 2024-11-17

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

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