Recent content by tsochiu

Yes, also can be by the photons.

...You still think I am doing the homework..... Actually, I am referring to the Franck-Hertz experiment. They have concluded from their experiment that the electrons in the atom only receive some except values of energy, for example, the excitation energy 4EJ . And in the case of photon, any...

So how about the excitation with an incident electron?

Excuse me, I found difficulties in understanding the physical terms as my teacher touches this topic recently. From my knowledge, to excite an electron from a certain obrital to another, we need a photon with energy exceptly the same as the excitation energy. Therefore, only light with certain...

You may see it as a way to transfer energy. I am not sure will the photon or electron "touch" each other.

I have some difficulties in studying the part of collision in quantum physics. Will a photon with energy 5EJ collides with a electron with the ionization energy 4EJ in the non-metal atom? (E is a constant) Will a bombarding electron with kinetic energy 5EJ collides inelasticly with a...

Thank for your patient in answering my questions. I have learned a lot from it.

I want to ask when will the total pressure be the same and when won't? Also, If the wind blow toward the building, will the wind have the same total pressure with the steady air behind the building?

Jeff Reid, thank for your clear explanation. Now I know that increase in dynamic pressure is more than increase in total pressure in this case. But it raise another question, how do we know when will the dynamic pressure increase more than the total pressure?

So the wind has the same total pressure with the steady gas if they appear in the same place, and only two isolated system will have different total pressure, isn't it?

I see, the total pressure is equal, but, in what situation, as a gas, the total pressure will change?

I'm sorry. I still can't understand it, the air passing between the two pieces of paper is in the same steamline with that from my mouth. But how about the air on the left side of the left paper and that on the right of the right one. They are in different steamlines with the gas I blowed out...

So it can not be used in this case, as total pressure is not the same with air in the room and the air I beathe out. My concern is in what situation the total pressure will change and when will it keep the same so that I can use the Bernoulli's equation

When I blow some air though two pieces of paper, the experience told me that two pieces of paper will move toward each other. However, there should be work done by me on the air I blowed that changes its total pressure. As there is a work done, we cannot simply apply Bernoulli's equation. So...

Your web page is really helpful. I can understand what is happening in the u-tube now. That is when the u-tube start to narrow,the wall of the u-tube will give a reaction force toward the liquid which will cancel out the extra force due to the wider mouth. Thanks for your help, it solve my...