"Friction" Motion and Force PPT Courseware 5

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"Friction" Motion and Force PPT Courseware 5

Force is what changes the state of motion of an object. It means that the object is acted upon by a force. We call this force friction.

1. Will football on grass finally stop?

2. Will a bicycle eventually stop if people don’t pedal?

3. When wiping the blackboard?

...Think about what other phenomena around you have friction?

Give it a try

1. Press your palms firmly against the table and push forward, but keep your palms still relative to the table.

2. Press the palm of your hand lightly onto the table and push forward so that your palm slides relative to the table.

1. Friction (F friction, f)

1. When two objects that are in contact and squeezing each other make relative motion (or have a tendency to move relative to each other), a force will be generated on the contact surface that hinders the relative motion (or tendency of relative motion). This force is called friction.

2. Conditions for generating friction

a. Two objects are in contact

b. Two objects have pressure

c. There is relative movement or a tendency of relative movement

d. The contact surface is not smooth

3． Direction of friction:

Opposite direction of relative movement or relative movement trend

4. The point of action of friction:

contact surface between objects

question

1. How to change the pressure of the wood block? How rough is the contact surface?

Movement speed? Contact area?

2. What tool is used to measure friction? How to test?

Spring dynamometer pulls the wooden block at a constant speed, the pulling force is equal to the friction force

3. What scientific methods are used?

Control Variable

The conclusion drawn by the control variable method should: emphasize conditions

2. Factors affecting the magnitude of sliding friction

1. When the roughness of the contact surface is constant; the size of the sliding friction force is related to the pressure on the contact surface. The greater the pressure on the contact surface, the greater the sliding friction force;

2. When the pressure on the contact surface is constant; the size of the sliding friction force is related to the roughness of the contact surface. The rougher the contact surface, the greater the sliding friction force.

The size of sliding friction has nothing to do with object weight, speed, and contact area.

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For more information about the "Friction Motion and Force" PPT courseware, please click the Friction ppt motion and force ppt tag.

"Friction" interaction PPT download:

"Friction" Interaction PPT Download Part One Content: [Learning Literacy and Objectives] Physical concepts: 1. Understand the conditions and directions of sliding friction and the factors that affect its magnitude, and master the formula for calculating sliding friction. 2. Understand Conditions for the generation of static friction..

"Friction" interaction PPT courseware:

"Friction" Interaction PPT Courseware Part One: Course Standard Requirements 1. Know the conditions under which sliding friction occurs, and be able to determine its direction and solve for its magnitude..

"Friction" interaction PPT:

"Friction" Interaction PPT Part One Content: Learning Objectives 1. Know the conditions under which sliding friction occurs, and be able to determine its direction and solve for the magnitude of sliding friction. 2. Knowing the conditions under which static friction occurs, you can determine its direction and solve for the magnitude of static friction.

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Update Time: 2024-07-30

This template belongs to Physics courseware People's Education Edition Physics for Grade 8, Volume 2 industry PPT template

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