Particles Definition and 1000 Threads

##\vec{L} = \vec{P} \times\vec{r}## ##L = mvr sin \phi##, where P = mv Since ##\vec{r}## and ##\vec{v}## are always perpendicular, ##\phi## = 90. Then, ##L = mvr## At this point, I don't see how to get ##L = mvr = mr^2\omega##, using ##\omega = \dot{\phi}## I know that ##\omega =...

I am not able to understand the following paragraph from my Physics textbook;

Hello! Let's say we have a wave function. Maybe it's in a potential well, maybe not, I think it's arbitrary here. This wave function is one-dimensional for now to keep things simple. Then, we use a device, maybe a photon emitter and detector system where the photon crosses paths with the wave...

When I read things about magnetism on internet, I don't understand at all about one thing: If a moving particle receive a force if it's in a magnetic field, so it should accelerate, so what happen if we change the referential so that the particle now don't move? The particle shouldn't receive...

First, I was not sure whether this should go into the Relativity or the Quantum Physics rubric, but since the central question is about entanglement, I opted for the Quantum. I do not have the necessary sophistication to follow string theory arguments, and even most explanations in...

I recall reading someone questioning if it were possible for the higgs boson to be the primordial atom which led to the start of the universe. I was just wondering if that could even be possible, since the higgs field was zero and couldn't have given these particles any mass. (please be kind...

Using the equation En = (h2*n2 ) / (8*m*L2), I got that E1 = 0.06017eV but the answer is not correct.

I am not that super expert of statistics, so feel free to shift my formulation of the problem into the right one.First, for a physicist, the basic formulation of the problem. Let us say that you have a gravitational field and you have a fully symmetric problem on a flat world without other...

Problem : The statement is given above. Here I attach the image of the problem to the right. Attempt : (1) Condition for collision : For the two particles to collide, there should be no relative velocity perpendicular to their "separation vector" ##\boldsymbol{s}##. Hence, we must have ...

The answer is dipole-dipole and London dispersion forces, but I only chose London dispersion forces. How would you determine whether there is a large or small electronegativity difference between N and O? And therefore how would you determine whether the N-O bond is polar covalent or non polar...

Two particles A and B are attached to the ends of a light inextensible string, which passes over a smooth pulley. Particle A has mass 8 kg and particle B has mass 5kg. Both the particles are held 1.2m above the ground. The system is released from rest and the particles move vertically. a) when...

Two particles A and B are attached to the ends of a light inextensible string, which passes over a smooth pulley. Particle A has mass 8 kg and particle B has mass 5kg. Both the particles are held 1.2m above the ground. The system is released from rest and the particles move vertically. a) when...

Do we notice any significant difference in distribution and dynamics of dark matter in galaxies when n-body simulations are done with high or low-mass dark matter particles?

My understanding is that virtual particles don't really exist. However, they somehow come into existence under certain circumstances. For example, in the Casimir Effect the virtual particles on the outside of the plate now have the capacity to transfer momentum and kinetic energy to the...

I am a non scientist and nonetheless a have the following question: once particles are (intrinsically) entangled do they always react in the opposite way/ anti-symetric to each other? Source https://www.physicsforums.com/forums/quantum-physics.62/post-thread

What is the difference between an anti particle and a super-partner? Would SIMPs fall under the supersymmetry theory, or the anti particle theory, or both?

Hi and thank you for answering questions on complex subjects like this. I’m a non-scientist who is jealous of your brain capacity! Recently, in a discussion with a chemist, he said the particles appearing from nothing might have been the initial cause of the universe. I’m familiar with the...

I am having trouble with the normalization part. To get a spin ##|32>## state I could have the following possibilities ##C_1|111110> + C_2|111011> + C_3|101111>## This should be equivalent to ##C_1|11>|21> + C_2|11>|21> + C_3|10>|22>## That is a spin 1 particle and a spin 2 particle that need...

I have no clue how to do this. Pls help

I calculated a=8m/s^2. I don't understand how to calculate the total time.

I got the speed of p when q reaches the pulleys = 1m/s, a= 2m/s^2 Iam getting time = 0.8s for q(b)

Friction= 1/(sqroot12)×80 cos 30= 20N I get two equations T-20=8a and 120-T=12a a=5m/s^2 I don't know how to calculate the time. Also with this value of acceleration tension value is wrong and the textbook ans is 84N

A passenger lift had mass 500 kg. The breaking tension of the cable is 12000N. The max acceleration of the lift is 0.75 m/s^2 a) if the lift travels at its max acceleration, calculate the max mass of the passengers: 1)when the lift is accelerating upwards 2) when the lift is accelerating...

A box of mass 20 kg sits on the floor of a lift. A second box of mass 10kg sits on top of the first box and a third box of mass 5kg sits on top of the second box. When the tension in the lift cable is 4260N, the lift is accelerating upwards at 0.5m/s^2. a) work out the mass of the lift. b) work...

A crate of mass 20 kg is put into a lift. The mass of the lift is 300kg. Find the tension in the lift cable. a) when the lift accelerates upwards at 0.3m/s^2 b) when the lift travels at constant speed c) when the lift accelerates downwards at 0.3m/s^2 For (a) is it T- W-w= ( M+m) a Where T is...

Two smooth pulleys are 8m apart at the same horizontal level. A light inextensible rope passes over the pulleys and a box of mass 5kg hangs at each end of the rope. A third box of mass m kg is attached to the midpoint of the rope and hangs between the pulleys so that all the three boxes are at...

A block of mass 4kg is held on a rough slope that is inclined at 30 degree to the horizontal. The coefficient of friction between the slope and the block is 0.2. A light inextensible string is attached to the block and runs parallel to the slope to pass over a small smooth pulley fixed at the...

A bucket of mass 3kg rests on scaffolding at the top of a building. The scaffolding is 22.5m above the ground. The bucket is attached to a rope that passes over a smooth pulley. At the other end of the rope there is another bucket of mass 3kg, which initially rests on the ground. The bucket at...

A car tows a caravan down a hill. The slope of the hill makes an angle theta with the horizontal, where sin theta = 0.05. The force from the car's engine is a braking force ( a negative driving force). The car has mass 1800 kg and the caravan has mass 600kg. The resistance on the car is 20N and...

I'm trying to get my head around the principles of quantum entanglement (would love to get some schooling on the issue but I don't have that kind of money) and trying to discern the actual science from the horrible misconceptions is difficult. I know you can't transmit information faster than...

A horizontal bar of mass 1kg hangs from a pair of parallel vertical rods of negligible mass, attached to either end of the bar. A third vertical rod is connected to the middle of the bar and a 4kg mass hangs from this below the rod. Work out the tension in each of the rods. I got the tension in...

A car of mass 2000kg pulls a caravan of mass 1200kg along a straight horizontal road. The resistance on the car is 20N and the resistance on the caravan is 80N. The max possible driving force from the car's engine is 1900N. The tow-bar will break if the tension exceeds 680N. a) Find the max...

I was wondering if the resulting daughter element is ionized after the parent undergoes beta(or any other kind) of radioactive decay,

So what I'm not sure on, is calculating the matrix elements for part (iii) with Pauli spinors and Pauli matrices, and then finding the form of the corresponding states. As I don't see how using the hint helps. The following is using the eigenvalues of the spin-operators. Provided what I...

qn iv. I understand that when 1.5 periods pass, every compression will become rarefaction, and every rarefaction will become compression(someone please correct if wrong) but the answer key shows something else. I'm interpreting the answer key drawing to be 1 compression and 4 rarefactions...

We have a question about highly energized beta particles (6 to 22 MeV). Is it possible fore this radiation to affect the nucleus of an isotope and not just ionize it? In our case a copper-65 and copper- 63 isotope become their unstable neighbors Cu-64 and Cu-62 due to the high beta radiation...

Hi, I was wondering if compacting a particle p, you could create an even more dense one. In my theory, you would have a particle of any material, (for example: copper) and you combine it with another copper particle, if you compacted it enough, would the density of the two particles be added up...

Maybe this will help.

I would greatly appreciate answers or perspective on these questions, thank you in advance! Since entangled photons are traveling at the speed of light relative to our spacetime, my understanding is that they experience no time or distance from the moment they are generated to the moment they...

I am having trouble to understand what it means by "physically relevant real parameters" and how does it help us to specify a quantum system. Let say, we have a state of k half spin electrons? My guess is about the local phase of the spin, and this would make it 2^k parameters since each...

To find the mass in other pan, i need to find the force caused by beads on the pan ∴ KEinitial + PEinitial = KEfinal + PEfinal 0 + mgh = ½ mv^2 => v = 3.13 m/s ∴ The change in momentum : p2 - p1 = m ( v2-v1) = m( v - (-v)) = 2mv ∴ F = Δp / Δt = n. m. v How can i apply the rate of 100...

I think it is quite simple as an exercise, following the two relevant equations, but at the beginning I find myself stuck in going to identify the lagrangian for a relativistic system of non-interacting particles. For a free relativistic particle I know that lagrangian is...

F= 9*10^9 (5*10^-9)^2 / (0.05)^2 a=F/m = F/(3*10^-6) v^2 = u^2 + 2aS = 0 + 2a*0.03 v = 60 Where did I do wrong? Thanks!

In some textbooks it is given that - Electric charge is the characteristic property of matter that causes it to experience a force when placed in an electromagnetic field. and In other textbooks it is given that - Electric Charge is the property of subatomic particles that causes it to...

How does gravity influence an electron beam? And how does it influence the other particles?

I am studying Modern Physics at graduation and several new particles are being presented, which I had not any contact with until now. I'm wonder if all these particles, which were recently discovered by Physics, have charge whose value is a multiple of the elementary charge of the electron or if...

When I asked my professors about quantum interpretations like whether it is particles or waves in the double slit experiment. They always say it is just quantum stuff which is neither particles nor waves, so one must not describe them at such. So why do we have so many interpretations. Why not...

Suppose we have two charged particles A and B released in the center of the Mirror (where the field is minimum). If A's velocity direction is parallel with the Magnetic field of the mirror and B's velocity is perpendicular with the field, then which one is going to get trapped, or escape, or...