Recent content by Ethan0718

Okay, you're welcome^^

Well, What do you mean by "interpreted physically"? Isn't those derivation sufficient to interpret it physically?

1. Your calculation is right. 2. Work is defined as the inner product of the force vector and the displacement vector. Assumption: (1)The object we're discussing is a mass point. (2)The net force on the object is the same in both frames. Let it be Fnet. (3)v+vc=v', so dr+drc=dr' In frame S...

You...Alright...I surrender. Thank you for all of your reply!

Oh! I admit that I didn't know you would say this. What if I ask you this : How do you know they're not the same thing? Will you think I should not ask this question? I think you should take the burden of proof because it's you that asserts they are not the same. By the way, you might be...

I REALLY fully agree with you but that's not what I meant. I'm not talking about the work done by the rope or us. I'm talking about how you describe the work done by the ground though frictional force. Premise 1: The frictional force is the interaction between the block and ground. Premise 2...

1-You're right, almost every textbook are using the method you mentioned to derive energy formula. However, it's still not compelling to say I'm wrong. Perhaps, all of those textbooks are wrong. Right? 2-Agree, no one would say NSL is the single law governing all of the universe but almost...

I see, you didn't say that's the heat transferred from ground to block. Hmm. Let me be clear about these things: 1. I do think FLT is the only single law which is capable of deriving any kind of energy formula. 2. I do think we cannot use, solely, NSL to derive any kind of energy formula. 3. I...

All what you've said is, without telling me your reasons which are based on physics law, not your intuition, I'm wrong and very, very confused. The final question you put toward me is what the definition of energy is. (Did I miss some questions you've asked me?) I've tried to tell you my...

Problem1 If the charge isn't distributed uniformly on its surface and we don't need to consider the electrostatic induction on the surface, then this question would be easy. It's like a point charge in the space. However, this leads to next problem: where do we need to calculate the electrical...

Yes! The direction of positive y-axis is arbitrary but you should be careful if you're not always set positive y-axis direction upward. Sometime you would forget your positive direction.

1. Position, velocity and acceleration has two properties: magnitude and direction. 2. The above three quantities manifests their direction with positive or negative sign. 3. The sign of acceleration can be shown by its definition, the time rate of change of instantaneous velocity. Just like...

Suppose that the positive y-axis is upward. so, if the velocity is increasing in negative y direction. For example: V_{iy}=-5\:m/s,\:V_{fy}=-10\:m/s,\:Δt=0.5\:s Then a_{avg,y}=\frac{V_{fy}-V_{iy}}{Δt} a_{avg,y}=\frac{(-10)-(-5)}{0.5}=\frac{-5}{0.5}=-10\:m/s^{2} So, even if the velocity is...

1.We also have electric field outside the wire. Do you know the potential difference? Roughly speaking, you can draw the electric lines from high potential to low potential in space. 2.As you've said, we have magnetic field outside the wire. So, we have to take the sum of electric...

Thanks for trying to read those papers. Your method has been discussed in this paper: Thermodynamics of a Block sliding Across a Frictional Surface by Carl E. Mungan You can also calculate the entropy in that process. At my first glance, I wonder whether the kinetic energy of center of mass is...