"The Effect of Pressure" Pressure PPT Courseware 3

Description

"The Effect of Pressure" Pressure PPT Courseware 3

Observe the picture below, do you think of any problems?

How can a tiny cicada insert its thin mouthparts into the thick bark of a tree?

How can a heavy camel carry heavy cargo in the soft desert?

Why do walkers have difficulty walking in the snow?

Why can skiers glide freely through the snow?

Why cars can't drive safely through mud

Why can tanks pass through swamps smoothly?

The concept of stress

(1). Pressure:

(1)Definition: ______The force acting on an object_____.

(2) Direction: _____ with the surface of the pressed object and pointing into its interior.

(3)Action point: on the surface of ______ object.

Exploration 1:

The relationship between the effect of pressure and the amount of pressure

hint:

Because the effect of stress may be related to multiple factors, it is necessary to use the control variable method appropriately during the exploration process.

Conclusion: The effect of pressure is related to the amount of pressure

Exploration 2:

The relationship between the effect of pressure and the force-bearing area

Conclusion: The effect of pressure is related to the force-bearing area

in conclusion:

1. When the force-bearing area is the same, the greater the pressure, the more obvious the effect of pressure.

2. When the pressure is the same, the smaller the force-bearing area, the more obvious the effect of pressure.

To compare the effect of pressure, you can compare the ratio of pressure to force-bearing area.

The elephant’s pressure on the ground = the elephant’s gravity = 60000N

The contact area between each foot of the elephant and the ground is 600cm², so the distance between the elephant and the ground

The total area is: 600cm²×4=2400cm²

Therefore, the ratio of pressure to force area is: 60000N/2400cm²=25N/cm²

The ballet dancer's pressure on the ground = her gravity = 475N

One of her feet is on the ground, so her contact area with the ground = 10cm²

Therefore, the ratio of the pressure she experiences to gravity is 475N/10cm²=47.5N/cm²

25N/cm²<47.5N/cm²

It can be seen from this that although the pressure of the elephant on the ground is greater than that of the ballet dancer, the effect produced is not as obvious as that of the ballet dancer.

How to increase pressure

When the pressure F is constant, reduce the stress area S

When the stress area S is constant, increase the pressure F

Increase the pressure F and reduce the stress area S

Ways to reduce pressure

When the pressure F is constant, increase the stress area S

When the stress area S is constant, reduce the pressure F

Increase the stress area S and reduce the pressure F

Study diary

1. The force acting vertically on the surface of an object is called pressure. The direction of pressure is always perpendicular to

An object under pressure and pointing towards the object under pressure.

2. Pressure: (in physics, pressure is used to express the effect of pressure)

1. Definition of pressure: The pressure exerted on an object per unit area is called pressure.

2. Pressure formula: P=F/S

3. Pressure unit:

In the International System of Units, the unit of force is Newton, the unit of area is meter 2, and the unit of pressure is Pascal, referred to as Pa, represented by the symbol Pa.

3. Methods of increasing and decreasing pressure

1. Methods to increase pressure: (1) When the stressed area remains unchanged, increase the pressure and increase the pressure; (2) When the pressure remains unchanged, reduce the stressed area and increase the pressure.

2. Methods to reduce pressure: (1) When the stressed area remains unchanged, reduce the pressure to reduce the pressure; (2) When the pressure remains unchanged, increase the stressed area and reduce the pressure.

Ability to Surf

1. A rectangular brick is placed on the ground. Among the different placement methods, the greatest pressure on the ground is ( )

A Place flat B Place on side

C. Place it vertically. D. The three placement methods are the same size.

2. Regarding pressure, which of the following statements is correct ( )

A. If the pressure is high, the pressure must be high.

B. If the stressed area is large, the pressure must be small.

C. If the force-bearing area per unit pressure is large, the pressure must be large.

D. If the pressure per unit stressed area is large, the pressure must be large.

3. When a piece of "Su Zhong Bao" is placed flat on the table, the pressure on the table is 0.5Pa. If the newspaper is folded in half, the pressure of the folded newspaper on the table is _____Pa. If half of the newspaper is torn off, the pressure exerted by the remaining part on the tabletop is _____Pa. Its physical meaning is _______________.

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For more information about the PPT courseware "The Effect of Pressure and Pressure", please click the "Pressure ppt Effect of Pressure ppt" tag.

"The Effect of Pressure" Pressure PPT Courseware 4:

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"The Effect of Pressure" Pressure PPT Courseware 2:

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Update Time: 2024-08-06

This template belongs to Physics courseware Shanghai Science Edition 8th Grade Physics industry PPT template

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