"Lever" Mechanical and Work PPT Courseware

Description

"Lever" Mechanical and Work PPT Courseware

Knowledge review

Leverage balance conditions:

(1) Content: Power multiplied by power arm equals resistance multiplied by resistance arm

(2) Expression: F1 ×L1=F2 ×L2

1. Application of Leverage Principle

[Research on the principle of steelyard]

[Principle] F1l1＝F2l2 m object gAO＝m mass gOB

m object = m mass OB/AO m object is proportional to OB

[Thinking] 1. Are the scale lines on the steelyard evenly distributed?

2. What impact will the rust of the scale weight have on the measurement results after long-term use?

3. There is a steelyard with double handles. What is the function of the double handles?

[Calculation of balance factors 1]

[Method] 1. Build a model rationally and clarify the balancing elements

2. Correspond to the leverage principle and implement formula deformation

3. Pay attention to the unity of units and standardize the problem-solving process

[Analysis of dynamic balance 1]

For example, as shown in the figure, the lengths of each square marked on a lever with negligible mass are equal, 0 is the fulcrum, each hook number hung on both sides of the lever is the same, and the lever is balanced in a horizontal position. In the following cases, the lever is still balanced in the horizontal position ( )

A. Reduce one hook code on both sides

B． Add an identical hook code under the hook codes on both sides.

C. The hook code on the left moves one space to the right, and the hook code on the right moves one space to the left at the same time.

D． Add a same hook code on the right, and move the hook code on the left one space to the left at the same time.

[Analysis of Dynamic Balance 2]

For example, as shown in the figure, a light lever can rotate around the axis O. A weight is hung at the midpoint of the straight rod. A force F is applied to the other end of the rod to slowly lift the straight rod from the lower right position to the horizontal position. During the positioning process, the change in the magnitude of force F is ()

A. Keep increasing B. Keep decreasing

C. Remain unchanged D. Unable to determine

[Determination of minimum power 1]

【method】

1. Reasonably determine the fulcrum O and the power action point

2. The connection point between the fulcrum and the power action point is the maximum power arm.

3. Draw the line of action to determine the effect of resistance.

4. Determine the direction of power according to the "principle of forward and reverse"

[Determination of minimum power 2]

It can be seen that the simple machine of lever still has important value

Keywords: Machinery and Work teaching courseware, Leverage teaching courseware, Beijing Normal University Edition eighth grade physics PPT courseware download, Volume 2, Eighth grade physics slide courseware download, Machinery and Work PPT courseware download, Leverage PPT courseware download, .PPT format;

For more information about the "Lever Machinery and Power" PPT courseware, please click the "Lever PPT Machinery and Power PPT" tab.

"Research on Leverage Tools" Tools and Machinery PPT download:

"Research on Lever Tools" Tools and Machinery PPT Download Part One: New Lesson Learning Find out the fulcrum, force point and resistance point of the iron piece, bottle opener and clamp respectively. What is the difference between their three o'clock positions? Among these three types of levers, which one is labor-saving and which one is labor-intensive?

"Research on Leverage Tools" Tools and Machinery PPT:

"Research on Lever Tools" Tools and Machinery PPT Part One Content: New Lesson Explanation (1) Comparison of Lever Tools Iron piece to open paint bucket lid Clamp to clamp object Bottle opener to open beverage bottle Find three of the three tools respectively Classification of levers at important positions...

"The Science of Leverage" Tools and Machinery PPT courseware download:

"The Science of Leverage" Tools and Machinery PPT Courseware Download Part One: Introduction of New Lessons Is there a strong man in our class? Can anyone help me lift the podium? One of my pens fell under the table. The podium is too heavy to move. Can I use tools to...

File Info

Update Time: 2024-09-27

This template belongs to Physics courseware Beijing Normal University eighth grade physics volume 2 industry PPT template

Preview