Why can't the internal force do work on the system at the position of resultant force =0? At first, I thought it was reasonable, because if the internal force can do work on the system, then the energy of the system can be increased indefinitely. But in chemistry class, when we learned that a cation absorbs an anion, the teacher went on to say: Because the potential energy of the system decreases and tends to a more stable state when the anion and cation approach, the two ions will always approach (that is, charge attraction = proton positive charge repulsion → static electricity). In this case, the potential energy decreases and the kinetic energy does not change. Then the energy of the system is reduced, and the internal force can do work on the system! What's the matter? 2. Tibet Honor Point 7: 00 (physics research is successful) Release time: 22: 37: 32 September 23, 2004 Location: Chiayi, Taiwan Province Province [Response to the previous article] The kinetic energy has not changed, which is the final equilibrium state. The change of kinetic energy should start with the tail _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ I still feel weird! It is not surprising what will happen in _ _ _ _ _ _ _ _ _. If two ions in a solution are close together, the potential energy will indeed decrease, but not too close, otherwise they will repel each other. The reduced potential energy is not converted into kinetic energy, but into the internal energy of the compound (because if converted into kinetic energy, two ions will collide, so the physical effects of repulsion will not combine). The purpose of combining these two substances is to stabilize. If we consider that the' collision' mentioned by Wang Cisu can only happen when the solution is heated, and it must be assumed that the collision is not completely elastic (otherwise there will be no heat release after the collision), heating the solution will increase the convection of the aqueous solution, that is, increase the speed of ions moving in all directions (so the kinetic energy will increase). The more collisions lead to free collisions, the faster the reaction rate, and the easier it is to cross the barrier of activation energy and combine [edited by Descartes on September 25, 200412: 27: 30] [edited by Descartes on September 25, 200412: 28: 313] 7: Freelance Hunter Honor Point 3: 00 (Institute) Release Time: 2004-09-2517: 08: Location: Taipei City, Taiwan Province Province [Response to the previous article] _ _ _ _ _ _ _ _ Nothing strange happened. Think about the difference between explosion and double-mass spring vibration system! It's all internal forces What is the difference? _ _ _ _ _ _ _ _ _ _ _ _ _ The view of the top floor and the map of the street corner _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Why can't internal forces do work on the system? At first, I thought it was reasonable, because if the internal force can do work on the system, then the energy of the system can be increased indefinitely. But in chemistry class, when we learned that a cation absorbs an anion, the teacher went on to say: As the anion and cation approach, the potential energy of the system decreases and tends to a more stable state, so the two ions will always approach the position where the resultant force =0 (that is, charge attraction = proton positive charge repulsion → static electricity). In this case, the potential energy decreases and the kinetic energy does not change. Then the energy of the system is reduced, and the internal force can do work on the system! What's the matter? When the resultant force of two ions approaches zero, is the velocity zero? (Don't forget to be accelerated by electricity when approaching) Just like a simple pendulum swinging to the lowest point, the resultant force is zero, but the horizontal speed is not zero, so it continues to swing, so two ions will continue to vibrate with the resultant force zero as the balance point, and the sum of kinetic energy and potential energy remains unchanged. It's through! _ _ _ _ _ _ _ _ _ _ _ _ The scenery on the top floor and the figure on the street corner are a particle (particle; Particles) vibrate (vibrate) under the influence of a restoring force that obeys Hooke's law is called a harmonic oscillator. (Harmonic oscillator) * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *. * * * * * * * * * * * * * * * * * * * * * * * * One-dimensional [This article was edited by DeKal on 2004-10-017: 04. Posted: 2004-10-01:08:16: Location: Taipei City, Taiwan Province Province [Response to the previous article] Because the electromagnetic force is discussed, it usually does not satisfy simple harmonic motion, unless it is a weak disturbance, it will still be a periodic movement. The mathematical description is more complicated. We learned in chemistry class that when a cation absorbs an anion, the teacher went on to say, because when the anion and cation approach, the potential energy of the system decreases and tends to a more stable state. I wonder if your teacher refers to the ions in the solution?