2. This infinity is purely a theoretical hypothesis, not a real point;

3. Setting infinity as zero potential point and zero potential surface only illustrates the relationship between infinity and the system we study.

No interaction;

When we calculate the potential of any point, theoretically we integrate the product of that point to infinity.

5. The calculation of the potential in this question is to integrate the product from one point in the ball to infinity.

The following is a detailed analysis of your topic:

1. From the integral formula you gave, this ball is not a metal ball, and there is no net charge inside the metal ball.

Without an electrostatic field, there is obviously an electric field in your topic, which is definitely not a metal ball. Integral is also a piecewise product.

Is to accumulate in the ball to the surface of the ball first, and then from the surface to infinity.

2. According to Gauss theorem, the electric field on the surface of a sphere is only related to the electric quantity inside the sphere, and has nothing to do with the electric quantity outside the sphere, so the electric field from inside to outside.

On the one hand, strengthen, on the other hand, weaken. Strengthening means that more and more charges are added to the calculation or contribute to the field strength; Weakening is

Refers to the charge in the protosphere, whose contribution to the field strength is getting weaker and weaker, but it is still strengthening as a whole. That is to say. , if

There is a charge moving from the inside out, and the electric field force is getting stronger and stronger.

3. After leaving the sphere, the contribution of all charges to the electric field is equivalent to that all charges are concentrated in the center of the sphere. The integral seems to be 2.

Point, in fact, is not established at the same time in the ball. The first part is built in the ball, just like sending the charge in the ball to the surface of the ball.

The work done, and then the second part outside the ball is established, and the off-ball integral represents the next work.

Physical work is the cumulative effect of force on space, so it is a general method to calculate work by integrating to infinity.

In fact, electric potential is energy and work, but this work is a specific work, which needs to transmit electricity per coulomb.

The work is finished. The earth's gravitational potential energy, Coulomb potential energy and Faraday induced electromotive force all mean this. Emf is a specific

That's what energy per unit charge means.

To sum up, the above calculation is to calculate the work done on the unit charge, the force inside the ball does work, and the force outside the ball continues to do work, isn't it?

There are two forces in the ball. You can also understand it the other way around. If we are electric charges, we will come from infinity and enter the inner ball.

Try hard before you score, and try again after you score. The above product method is

Calculate the total energy we need. However, the calculation is from the inside out.