Mechanics Definition and 999 Threads

In R Shankar text on “principles of quantum mechanics’ discussing the adjoint operation, 1.3.8 shows that a|V> => <V|a*. Then 1.3.9 then states that <aV| = <V|a*. Is this a typo error?

Recently I started wondering why there seems to be so few practical/engineering applications where you need to calculate the momentum of something. I must emphasize that I don't mean usage of the concept of momentum or the law of conservation of momentum, but the value of the quantity itself...

(So this is the system given) The following is my analysis: (i) (ii) Well, my problem is - I got a negative acceleration and its quite impossible to have block B moving to the left. So I am wondering if there are any mistakes I've made.

How do "sinϕ - cosϕ sinϕ" become 0 ?

First I found partition functions of both the systems and hence total energies of them using above formulas. Z(A) = (1 - e-ε/kT)-1 and Z(B) = (1 + e-ε/kT) Then I equated these values to the given values of total energies. I got: For System A, T(A) = ε/kln(2) > 0 For System B, T(B) =...

Summary:: I have solved the question but I'm getting answers wrong, some reaction equations seems to have trouble. Question: Let m1 = 1 kg, m2 = 2 kg and m3 = 3 kg in figure. Find the accelerations of m1, m2 and m3. The string from the upper pulley to m1 is 20 cm when the system is released...

Upto now I've only dealt with the problems regarding non - degenerate energy states. Since bosons do not follow Pauli's Exclusion Principle, three bosons can be filled in two energy states (say E1 and E2) as: E1 E2 1 boson 2 bosons 2 bosons 1 boson 3 bosons 0 bosons 0 bosons 3...

Is Hamiltonian mechanics a mathematical generalization of Newtonian mechanics or is it explaining some fundamental relationship that has a meaning that extends into our nature ? I guess my question is what would led William Rowan Hamilton to come up with his type of mechanics or anything...

Regarding the first part, I proceeded as: nx ny nz 4 0 0 => E1 = 16C 0 4 0 => E2 = 16C 0 0 4 => E3 = 16C 3 1 0 => E4 = 10C 3 0 1 => E5 = 10C 0 3 1 => E6 = 10C 1 3 0 => E7 = 10C 0 1 3 => E8 = 10C 1...

I am working on a project where I have to calculate various results relating to the motion of a water bottle rocket being launched. I am currently stuck on trying to find how long the thrust period of the rocket is. The model for the rocket is as follows: It is a 2L (0.002m3 bottle filled with...

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I see this sort of wording a lot, for instance, we might say that the block is on the point of slipping or the ball is on the point of leaving the surface of the hill. My guess is that it's to do with constraint forces; that is, at the exact point where the constraint forces acting on a body can...

If anyone has an idea for an experiment or has any kind of manual containing experiments related to mechanics, that would really be helpful. If you have an idea like a new way to find moment of inertia of given object or anything like that, please do tell. I would really love to try it. Thanks

Well, the problem suggests to analyse it in a system attached to the wedge. If mass m ball is slipping upwards then it would have an acceleration along the wedge pointing upwards (in the suggested system). The forces acting on that ball would be the weight, a normal and a force due to the...

As you can see from the very last line of my post, this whole post may come from the fact that I don't get sarcasm o0)Hi, reading the above mentioned book I ran into the following footnote: Postulate A was earlier stated as: An alternative, but equal, version of Postulate A is given the page...

Hi! My first question: How does he get the equation ##\frac {x_A} {2πr_1} = -\frac {θ} {2π}## ?

Summary:: Is there somebody can help me？ The book about Mechanics analysis or classical mechanics,if you have read some good books, please recommend them to me, I will be very grateful.

M = r x F r = 0 ∴ M = 0 But this is clearly wrong. For some reason, the "reaction moment" must exist. Why? Where does it come from? More specifically, which force(s) produces the bending moment, and at what distance(s)? Does it come from the reaction force form the wall on the left end of the...

Hello, I am a computer science major and Ex-Biology grad student, my knowledge in physics is humble, but I got a little curious when my professor derived the expressions of moment of inertia for different objects. The moment of Inertia of a thin disk is 1/2MR2, but it is the same as the moment...

So far, I have this: For Part ii) I know that: mgh = xmgsin(theta), but I don't know how to go further

Hi there, I am an undergrad 1st year student in Physics. I wanted to self study the classical mechanics so that i can get hold of some very important concepts before it begins to rush in our class. Can you suggest me a basic Classical Mechanics book of undergrad level that will help to learn...

Hi, I am an undergraduate student in the 3rd sem, we have Lagrangian Mechanics in our course but I am unable to follow it properly. Can you please suggest me a book that will introduce me to Lagrangian and Hamiltonian Mechanics and slowly teach me how to do problems. I am beginner, so please...

This is what I have so far, please need urgent help. I don't understand and know what to do. For the first part, I got a really long answer, for the second part I am trying in terms of mv^2/r = mg, or mg = m*(answer to first), but I am getting nowhere. PLease help

There was an old thread comparing the difficulty of classical mechanics and electromagnetism. The consensus was that electromagnetism is more difficult, and substantially so according to some. The thread was no longer open for replies, but it got me suspecting that we're comparing apples to...

I'm a college freshman who might major in physics, but I'm still undecided. This semester, I registered for Classical Mechanics (intermediate, not introductory) but have lately reconsidering this. There are a few reasons for this: 1) I feel a little behind on math. I just started multivariable...

I have some doubts about ballistic pendulums. First, we say that if a bullet hits the pendulum, the linear momentum is conserved. But when we consider a rod attached to a pivot at one of its ends instead of a pendulum we say that the linear momentum isn't conserved because the rod can't move...

Hello, I am struggling with what each piece of these equations are. I generally know the two rules that need to hold for an operator to be linear, but I am struggling with what each piece of each equation is/means. Lets look at one of the three operators in question. A(f(x))=(∂f/∂x)+3f(x) I...

I tried this but I don't know if it makes sense: Average velocity from A to B = 22/2 = 11m/s Average velocity from B to C = 104/4 = 26m/s (26-11)/6 = 3.75m/s

By Fluid Mechanics I mean the mechanics of fluids, both at rest and in motion. I'm unable to find introductory books on Fluid Mechanics which contains everything in itself, for example I downloaded Fundamentals of Fluid Mechanics by Munson, Young, Okiishi, Huebsch and I don't know why but I...

I know we can't use classical mechanics to describe or measure the quantum. That is not what I'm asking. I am asking whether particles still follow the same rules like action/reaction if there is a force involved. If electron A interacts with electron B, is Newton's 3rd law still being applied...

Summary explains it.

Suppose the Bell operator ##B=|AB(1,2)+AB(1,3)+AB(2,3)|## With ##AB\in{1,-1}## Nonlocal realism implies ##B\in{1,3}## However using usual matrix sum one eigenvalues for the result of measurement can be smaller than 1, implying nonlocal realism cannot explain the quantum result. However if...

Hi I am reading Landau's mechanics So in the first chapter page 5 It reads : since space is isotropic, the lagrangian must also be independent of the direction of v , and is therefore a function only of it's magnitude ... I can't understand why , I think Landau's book has many fans in this...

https://www.nature.com/articles/d41586-020-00120-6

After much deliberation I can finally see and understand what you have all spent so much time and patience explaining to me! I can see that to observe the 2nd postulate; 'the speed of light in a vacuum is the same for all observers, regardless of the motion of the light source or observer' a...

I have measurements of period time and distances that's all: T (sec) D (m) 0.9 0.008 0.91 0.009 0.97 0.01 0.98 0.011 1.06 0.012 I thought about adding the magnetic force like: T=2π*√l/(g+x) but have no clue how to integrate the distance there, I don't know even how to start...

Can someone please tell me what is the name of below formula? ##H = z + \frac{v^2}{2g} + \frac{p}{γ}##

I'm self studying so I just want to ensure my answers are correct so I know I truly understand the material as it's easy to trick yourself in thinking you do! A particle of mass m is in a 1-D infinite potential well of width a given by the potential: V= 0 for 0##\leq## x ##\leq## a =...

Greeting, I wanted some suggestion regarding classic and essential papers to read in Classical Mechanics. The first semester is over, and I want to expand upon what I have learnt. If there is some paper or topic in particular that you found interesting personally early on, it would be helpful. I...

According to Nobel laureate Frank Wilczek, the universe emerges from a Grid. This was proposed in his book "The Lightness of Being: Mass, Ether, and the Unification of Forces". He also likes the idea that the universe emerged from a state of "nothingness" (or rather, a quantum vacuum) where...

It's 13 week plan. I need your feedback to improve it

I solved this question until the end of the "c)Find the distance until the boat completely stop" However I can not solve the integral I encounter in the solution of the last part of c). Would you please check for math and maybe my mistakes and tell me what to do? Here:

I believe I solved this. Is this solution true? Can please anyone just check?

Please help please

Hi folks! I was teaching myself rotational motion when encountered an example which states as follows: My questions: 1. I do not understand why pulling the cord moves the rotating spool to the right. There were some discussions on stackexchange...

Hello everyone ! I've got a problem in engineering class with a braking system (picture linked). In the first part I calculated the friction force $$ \vec{B} $$ with components : T (following y axis) : 2073.6N N (following x axis) : 5760N. For the first question I struggle a lot because I...

Hello everybody We saw a fracture in a switch rail, now we're trying to find the reason, may be you can help us. This rail is made of R260 steel. Let me know if any other information is needed. I have attached pictures of this rail. Thanks in advance

Regarding the paper Bohmian mechanics for instrumentalists I like the ideas put forward in the paper because it provides a basis for an intuitive and logical explanation of quantum mechanics. I have many questions about it, but I will start with 3. Question 1: In this interpretation, what is...