In the physical sciences, a particle (or corpuscule in older texts) is a small localized object to which can be ascribed several physical or chemical properties such as volume, density or mass. They vary greatly in size or quantity, from subatomic particles like the electron, to microscopic particles like atoms and molecules, to macroscopic particles like powders and other granular materials. Particles can also be used to create scientific models of even larger objects depending on their density, such as humans moving in a crowd or celestial bodies in motion.
The term 'particle' is rather general in meaning, and is refined as needed by various scientific fields. Anything that is composed of particles may be referred to as being particulate. However, the noun 'particulate' is most frequently used to refer to pollutants in the Earth's atmosphere, which are a suspension of unconnected particles, rather than a connected particle aggregation.
Hi there,
I am currently looking to build a rotating kiln to provide the necessary heat/res. time/gases to react a solid feedstock. The problem that I can envision, however, is that the solid (which is fed as small particles) may become entrained in the counter-current gas flow inside the...
I always struggle to know which force (strong nuclear, electromagnetic, weak, gravity) is responsible for an interaction. For example,
pi+ + pi- = neutron + pi0
I would say its strong force responsible, because quarks are involved. But the pions are also charged, so how do I know it's not...
Homework Statement
Viewers of Star Trek have heard of an antimatter drive on the Starship Enterprise. One possibility for such a futuristic energy source is to store antimatter charged particles in a vacuum chamber, circulating in a magnetic field, and then extract them as needed. Antimatter...
There seem to be many kinds of examples where the behavior of a quantum particle having been constrained to move on a curve or surface is investigated. The simplest is the case of a particle on a circular path or a spherical surface, where the energy eigenstates are equal to the angular momentum...
As per news from the CERN, the Eggeron or the "Humpty-Dumpty" particle has been discovered. Quoting from the news article:
The LHCb experiment at CERN’s Large Hadron Collider (LHC) has announced the discovery of Eggeron ##\eta_{gg}##, familiarly known as the “Humpty Dumpty” particle, the...
Hi everyone, I'm a senior undergrad in an Astrophysics BSc, and I just started my first course in Particle and Nuclear Physics.
Our teacher didn't suggest anything as a textbook, and on my own I couldn't find any really relevant/useful book for my course type, and now I'm here, hopefully having...
Homework Statement
A particle moves in a straight line with the acceleration shown in the figure.
Knowing that it starts from the origin with ##v_0 = -14ft/s##, plot the v-t and
x-t curves for 0 < t < 15 s and determine (a) the maximum value of the velocity
of the particle, (b) the maximum...
Homework Statement
A particle is moving in a 1-dimensional harmonic osciallator with the hamiltion:
## H = \hbar \omega (a_+ a_- + \frac{1}{2})##
at time ## t=0## the normalized wave function is given by
## \Psi(x,0) = \frac{1}{\sqrt{2}}(\psi_0(x) + i\psi_1(x)) ##
Task: Calculate for ## t \geq...
Homework Statement
11.10 The acceleration of a particle is directly proposional to the time t.
At t = 0, the velocity of the particle is v = 16 in./s. Knowing that v = 15 in./s
and that x = 20 in. when t = 1 s, determine the velocity, the position, and
the total distance traveled when t = 7s...
Homework Statement
11.8 The motion of a particle is defined by the relation ##x=t^3 - 6t^2 - 36t - 40,
where x and t are expressed in feet and seconds, respectively. Determine
(a) when the velocity is zero, (b) the velocity, the acceleration, and the total
distance traveled when x = 0...
Homework Statement
How much work should be done on a point charge of q=15 nC to bring it from infinity to a distance of 3 cm from a surface of a charged sphere? Diameter of sphere is 15 cm, its surface charge density is 12 microC/cm2
Homework Equations
W=deltaU=q*deltaV
v=kQ/r...
Homework Statement
11.7 The motion of a particle is defined by the relation ##x = 2t^3 - 15t^2 + 24t + 4
where x is expressedin meters and t in seconds. Determine (a) when the velocity zero ,
(b) the position and the total distance traveled when the acceleration is zero
Homework EquationsThe...
Homework Statement
The motion of a particle is defined by the relation ##x = 6t^4 - 2t^3 - 12t^2 + 3t + 3##, where
x and t are expressed in meters and seconds, respectively. Detrmine the time, the position,
and the velocity when a = 0.
Homework EquationsThe Attempt at a Solution
[/B]
Can...
Homework Statement
Find the velocity ± and the position x as functions of the time t for a particle of mass m, which starts from rest at x =0 and t =0, subject to the following force functions:
(a) Fx = F0 + Ct
(b) Fx = F0 sin Ct Ct
(c) Fx = F0e^ct
where F0 and c are positive constants...
Homework Statement
A particle of mass ##m## moves without slipping inside a bowl generated by the paraboloid of revolution ##z=b\rho^2,## where ##b## is a positive constant. Write the Lagrangian and Euler-Lagrange equation for this system.
Homework Equations...
In my introduction to quantum mechanics, I learned about the particle in a box, followed by the quantum harmonic oscillator. In both instances, zero energy was not possible; the ground states had non-zero energy.
However, in deriving the solutions to the Schrödinger equation for a particle on a...
The single photon experiment of Grangier showed that if a phase shift ##\theta## is introduced in one arm of a Mach-Zehnder interferometer then there is interference when the two beams are recombined - even if only one photon is introduced.
If a particle encounters a double slit of suitable...
I read somewhere that, suppose a scalar field Σ transforms as doublet under both SU(2)L and SU(2)R, its general rotation is
δΣ = iεaRTaΣ - iεaLΣTa.
where εaR and εaL are infinitesimal parameters, and Ta are SU(2) generators.
I don't quite understand this. First, why does the first term have...
Homework Statement
A particle of mass m is moving on a frictionless horizontal table and is attached to a massless string, whose other end passes through a hole in the table, where I am holding it. Initially the particle is moving in a circle of radius ##r_0## with angular velocity ##w_0##, but...
Homework Statement
[/B]
The position of a particle as a function of time is given by
r(t) = i(1 - e^-kt ) + je^kt
where k is a positive constant. Find the velocity and acceleration of the particle. Sketch its trajectory.
Homework Equations
v (t) = dr/dt
a(t) = dv/dt
The Attempt at a Solution...
Consider two virtual entangled particles (+ve & -ve particles) which emerged out of nothing.
We keep +ve and -ve in two different boxes. If the box containing +ve particle is closed and we do not observe the particle, then it is said to be in a superposition of +ve and -ve, Right? After some...
Homework Statement
Homework EquationsThe Attempt at a Solution
I don't understand what is y-axis representing ? What is V(x) ? Is it potential energy ?
Since the graph is a parabola , V(x) = kx2
I don't know how to proceed further .
Homework Statement
A bound particle is in a superposition state:
\psi(x)=a[\varphi_1(x)e^{-i\omega_1t}+\varphi_2(x)e^{-i\omega_2t}]
Calculate <x> and show that the position oscillates.
Homework Equations
<x>=\int_{-\infty}^{\infty} \psi(x) x \psi^*(x) \mathrm{d}x
The Attempt at a...
Homework Statement
Homework EquationsThe Attempt at a Solution
I am not quite understanding what is given in the question .Are the two directions of the fields known to us ?
Assuming we know the two directions , say for example if we know that the two fields are in x and y directions , but...
Homework Statement
Derive an equation for the velocity vx(t), vy(t) of the particle. - my teacher writes this oddly, that means the velocity in the x direction at any point in time, and the velocity in the y direction at any point in time.
Calculate the initial velocity of the particle...
Good day all!
I have a question that has been in my head bouncing around for a while and I figured the best resource would be here as I can't find anymore related information (Or I am just looking in the incorrect spot). My apologies if this is in the wrong section I wasn't too sure where to...
If I were able to accelerate a particle to relativistic speeds, then capture that particle in a box in such a way that it kept its speed, then weighed that box, would it weigh more than the box + rest weight of the particle? Would it exert a gravitational field greater than that of the box with...
Question:
A) A small charged sphere is attached to a thread and placed in an electric field. The other end of the thread is anchored so that the sphere is in a static situation when placed in the field. If the thread is horizontal, find the magnitude and direction of the electric field. The...
Homework Statement
I am given the Hamiltonian of the relativistic free particle. H(q,p)=sqrt(p^2c^2+m^2c^4) Assume c=1
1: Find Ham-1 and Ham-2 for m=0
2: Show L(q,q(dot))=-msqrt(1-(q(dot))^2/c^2)
3: Consider m=0, what does it mean?
Homework Equations
Ham-1: q(dot)=dH/dp
Ham-2: p(dot)=-dH/dq...
So I have read that particle that move near the speed of light can separate virtual particle for there anti-particle counter-part creating a new particle from the energy put in, but would this effect happen in particle accelerators like the large hadron collider, sorry if I am misinterpreting...
Homework Statement
Two positive point charges Q are located at points (±l, 0). A particle with positive charge q and mass m is initially located midway between them and is then given a tiny kick. If it is constrained to move along the line joining the two charges Q, show that it undergoes...
I will soon start with the course introduction to QFT and are hence an amateur on the subject.
However I could not help but wonder,
If particles are describes by oschlliations in a field, how can a "bigger body" be made up of several such oscillation? (A bigger particle is made out of several...
Homework Statement
In frame S particle 1 is at rest and particle 2 is moving to the right with velocity u. Now consider a frame S 0 which, relative to S, is moving to the right with velocity v. Determine the value of v such that the two particles appear in S' to be approaching each other with...
Homework Statement
A horizontal beam of laser light of wavelength 486 nm passes through a narrow slit that has width 0.0590 mm . The intensity of the light is measured on a vertical screen that is 2.90 m from the slit.
What is the minimum uncertainty in the vertical component of the momentum...
The equation of motion for a charged particle with mass ##m## and charge ##q## in a static magnetic field is:
##\frac{d}{dt}[m{\dot{\vec{r}}}]=q\ \dot{\vec{r}}\times \vec{B}##
From this, we can see that ##\frac{d}{dt}[m\dot{\vec{r}}-q \vec{r}\times \vec{B}]=0##
and so the following quantity is...
There is solid empirical evidence that error in particle physics measurements is not actually distributed in a Guassian manner. Why don't particle physicists routinely use student t error distributions with fat tails that fit the reality of errors in experimental measurement more accurately...
Homework Statement
Nitrogen-17 emits a Beta particle to form an isotope of Oxygen.
Use the following data to find the expected energy of the Beta particle.
Mass of N-17 = 17.00845 u
Mass of O-17 = 16.99913 u
Mass of Beta particle = 0.00055 u
Unified mass unit (u) = 1.66 x 10-27kg
Speed of...
Hi everyone,
I am currently working on a project in Physics analyzing the possibility of magnetic fields protecting against radiation particles such as fully ionized nuclei or electrons. I wrote a code in Matlab that simulates a 3-D magnetic field based on a combination of wires and wire loops...
Homework Statement
There is a charged particle at height h over a circular area of radii R, then I have to calculate the capacitance. This is useful when somebody want to calculate energy harvesting, antennas, sensors that measures ions in plasma devices and particle accelerators...
Hello,
I'm currently doing the project and need to estimate the force that will act on the micron size superparamagnetic particle in the field of permanent magnet.
I found several article there similar problem is solved, but I a bit confused. I hope someone could hep me.
So, the main equation...
Homework Statement
A particle of mass 7.3 × 10−5 g and charge 24 mC moves in a region of space where the electric field is uniform and is 6.3 N/C in the x direction and zero in the y and z direction. If the initial velocity of the particle is given by vy = 4.1 × 105 m/s, vx = vz = 0, what is...
The 4-momentum of a massless particle traveling in the z direction is (k, 0, 0, k). What is the significance of the value of k? It does not determine the speed since they always travel at light speed. If one particle has momentum (k, 0, 0, k) and another has (j, 0, 0, j) with j not equal to...
I'm reading up on the Lagrangian equation, but what I'm asking is to do with electromagnetism.
In the first equation here: http://www.phys.ufl.edu/~pjh/teaching/phy4605/notes/chargelagrangiannotes.pdf
L equals the kinetic minus the potential energy. For the potential energy term, I just don't...
Hi! I want to start solving problems from the text
'Orbital Mechanics for Engineering students' by Curtis 2nd edition.
Is this the right place to post?
Homework Statement
2.1 Two particles of identical mass m are acted on only by the gravitational force
of one upon the other. If the distance d...
Hi all,
I recently learned the concept of Maxwell's speed distribution and became interested in how to use similar momentum distributions to study the probabilistic motion of a classical free particle. I have done some of my own reading on probabilities and distributions (no formal lessons yet)...
I am about to teach some of an introductory course for bachelor students in the field of medical physics. More specifically the topic "Photon and charged particle interactions with matter" in respect to radiation therapy (again, medical physics). I know there are a lot of topics within radiation...