On the application of the holistic approach 50, on the application of the holistic approach

Whether the overall method can be used depends not only on the force and motion, but also on what needs to be solved.

Generally speaking, the principle is that motion is relatively stationary or relatively uniform, i.e. there is no "internal" acceleration. Because both of them are balanced by force at this time, or have an equal acceleration, they are equivalent in terms of being affected by external forces, and can be regarded as a whole.

I don't know what you said about "why can you use the integral method to solve the object that is not affected by external forces and accelerates its downward slope along the inclined plane", nor do you know how you use it. For example, if the pressure of the inclined plane on the ground is required, it is obvious that the object and the inclined plane cannot be regarded as a whole, and the pressure is equal to the sum of the gravitational forces of the two. If you can make the question clearer, I think it will be more beneficial for our discussion.

I think your conclusion, while correct, is still flawed in the analysis process. What about your "external force" package that doesn't include the friction of the bevel on the object? I don't quite understand your analytical process.

The object has acceleration, which means that the system has acceleration, then the system has an external force in the horizontal direction, so the inclined plane is subject to frictional force, do you analyze it like this? If this is the case, then the "integral method" is only used to push out the horizontal external force of the system, and whether this force is ground friction or not is the next step of the process.

How do you use the whole method for sliding and falling wooden blocks on the inclined plane?

You can't pursue this thing too much, how to use it, and there is no fixed way to learn it.

You've got the best of the horns.

It can be used, but it doesn't have to be relatively static. Accelerating the decline has acceleration, the application of the global method can analyze the force of the inclined plane and the ground, but can not analyze the force of the inclined plane and the slider, when applying the global method, first confirm whether the research object can be shown by the overall method, and then pay attention to the external force is external, nonsense, but some people often forget.

There is no big difference between the two questions!

In the first question, the acceleration is a

Then there is: a asin

According to the holistic law:

fsin +(m+m)g-fn=ma +m 0fsin +(m+m)g-fn=masin +m 0 because f ma (f+mgsin -umgcos =ma, and umgcos = mgsin, f ma can be obtained).

Substituting the above equation, we get: fn=(m+m)g

You have written a lot of content, I don't know if it has completely solved your doubts!

If you still have questions about this, please ask!

The holistic approach in physics refers to the method of analyzing and studying the entire system or process in a physical problem. In mechanics, several objects are regarded as a whole as the object of study, and when the force is analyzed, only the force of the object outside the whole object on the whole (external force) is analyzed, and the interaction force between the whole (internal force) is not considered. The whole is to take the object system as the research object, grasp the essence and laws of physical phenomena from the whole or the whole process, and is a kind of thinking form that combines multiple objects, states, or physical change processes with interconnection, interdependence, mutual constraint and interaction as a harmonious study.

Holistic thinking is a kind of comprehensive thinking, and it is also a high degree of synthesis of multiple thinking, with deep level, strong theory and high application value. Therefore, in the research and study of physics, he is good at using the whole research to analyze, process and solve problems, which is manifested as the synthesis of knowledge on the one hand, and the organic combination of thinking on the other hand. The flexible use of holistic thinking can produce extraordinary effects, show the charm of "change", and make physical problems simple and difficult.