"Why Shadows Change" Flagpole and Shadow PPT Courseware 2

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"Why Shadows Change" Flagpole and Shadow PPT Courseware 2

Conditions for shadow generation:

What are the conditions needed to see clear shadows?

Have light and opaque objects.

To see a clear shadow, you must shine light on an opaque object to see it.

light opaque object shadow

What else did you discover?

The shadows are all on the side of the object facing away from the sun; at the same moment, the shadow direction of any upright object is the same.

Communicate observations and explore characteristics

Characteristics and rules of shadow changes of objects under sunlight:

In the morning, the sun is in the east, and the shadow of an upright object points to the west. As time goes by, the height of the sun gradually increases, and the shadow changes from long to short;

At noon, when the sun is in the southern sky, the shadow of an upright object points due north, and the shadow length is the shortest;

In the afternoon, when the sun is in the west, the shadow of an upright object points to the east. As the height of the sun gradually decreases, the shadow changes from short to long.

During the day, the shadow is shortest at noon and longer in the morning and evening.

Why do shadows change?

Speculation:

Experiment:

Draw a picture:

Discussion: How are the changes in the shadow of the flagpole formed?

The changes in the flagpole's shadow throughout the day are caused by the Earth's rotation. Due to the rotation of the earth, the sun rises in the east and sets in the west. The higher the sun is, the shorter the shadow is. As the sun's position changes, the shadow's position changes accordingly.

Explore why shadows change

Choose appropriate materials to make the "flagpole" and use flashlight light instead of sunlight for observation.

How does the "flagpole shadow" change when the flashlight is moved consistent with how the actual flagpole shadow changes throughout the day?

Discussion: The relationship between shadow length and temperature changes

Changes in the object's shadow length and temperature are caused by the movement of the sun.

The change in the shadow length of an object under sunlight is actually the change in the height of the sun.

When the shadow is long, the temperature is low; when the shadow is short, the temperature is high.

summary:

The shadow is long - the altitude angle of the sun is small - the temperature is low;

The shadow is short - the sun's altitude angle is large - the temperature is high

Explore why shadows change

Discussion: What is the connection between the movement of the sun, the shadow length of an object, and the temperature?

For the same object at the same place during the day:

From morning to noon shadows gradually become shorter and temperatures gradually increase;

From noon to evening the shadows gradually become longer and the temperature gradually decreases.

Multiple choice questions

1.The relationship between the sun and the shadow is ( ).

A When the sun rises in the east, the shadow also rises in the east

B The shadow moves with the movement of the object and is not affected by the sun

C The positional relationship between the shadow and the sun is relative. If the sun moves, the shadow will also move with it.

2. The temperature changes during the day are morning and evening ( ) and noon ( ).

A lower B highest C all the same

3. The changing pattern of the sun's position during the day is ( ); the changing pattern of the shadow's position is ( ); the changing pattern of the sun's height is ( ); the changing pattern of the shadow's length is ( ).

A from west to east B from east to west

C low to high and then low D from low to high

E From short to long and then to shorter F From long to short and then to longer

True or False

1. The direction of the shadow is the same as the direction of the sun. ( )

2. The higher the sun is, the longer the shadow of an object. ( )

3. The changes in the position of the sun in the sky are closely related to our lives. ( )

4. Temperature changes throughout the day are related to the position of the sun in the sky. ( )

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For more information about the "Flagpole and Shadow Why the Shadow Changes" PPT courseware, please click the Flagpole and Shadow ppt Why the Shadow Changes ppt tag.

"Why Does the Shadow Change" Flagpole and Shadow PPT Courseware 4:

"Why does the shadow change" Flagpole and Shadow PPT Courseware 4 Conditions for shadow production: What conditions are needed to see a clear shadow? Have light and opaque objects. To see a clear shadow, you must shine light on an opaque object to see it.

"Why Does the Shadow Change" Flagpole and Shadow PPT Courseware 3:

"Why Shadows Change" Flagpole and Shadow PPT Courseware 3 Teaching Objectives: 1. Through teaching, let students know the movement pattern of the sun in the sky every day; understand that the changes in temperature and shadow throughout the day are related to the movement of the sun. 2. Able to use simple measuring tools..

"Why does the shadow change" flagpole and shadow PPT courseware:

"Why Does the Shadow Change" Flagpole and Shadow PPT Courseware Conditions for shadow production: What conditions are needed to see a clear shadow? Have light and opaque objects. To see a clear shadow, you must shine light on an opaque object to see it.

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Update Time: 2024-10-02

This template belongs to science courseware E-education edition fourth grade science volume 1 industry PPT template

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