Mass Definition and 1000 Threads

[Mentors' note: There's no template because this thread was moved from General Physics. The specification of the problem seems adequate without the template] Hi everyone, I am working through stuff based on the Millikan Oil Drop experiment. There is a question that asks to determine the mass...

Homework Statement A system consists of a mass m moving in one dimension and attached to a rigid wall by a spring having stiffness constant ##K##, as shown. The mass is subjected to a constant force ##F##, and is in equilibrium with the surroundings at a temperature ##T##. The partition...

I have made an attempt at the question below and just wanted to check if my thinking was correct or totally wrong. Thank you in advance! 1. Homework Statement In a simple model of a star, the density is described as ρ=ρ0(1-r/R), where R is the stellar radius, and ρ0 is the central density...

Does a photon have mass?

Hello everyone, Can the mass flow rate of air by a propeller connected to an engine through a small tube change if the rpm of the propeller is increased?

I have studied that mass transfer is of two types Molecular mass transfer(diffusion) Eddy diffusion then in later portion of the book I found that there is convective mass transfer too, I wanted to ask if both convective mass transfer and eddy diffusion are same ? I read this equation N_i =...

How could we detect negative mass matter? The only proposal I've ever heard of is that we could detect there's a cutoff frequency in the gravitational waves we receive, due to attenuation of those lower frequency waves by negative matter. Are there more experiments that could be conducted...

does somebody with a negative mass create a white hole instead of a black hole because of its anti gravity property.

Homework Statement Does amplitude of an oscillating spring with an attached block depend on the block's mass? Assuming the spring has spring constant 'k' and obeys Hooke's law. How would the amplitude of the oscillating spring system be affected if the mass of the block were...

In most treatments of the mass renormalisation in dim reg, I see sources find the mass counter term by extracting the coefficient of e.g the ##m^2## term accompanied by a pole in epsilon. I know the mass counter term is found by placing an X on diagrams where there is usually a self energy...

Homework Statement Two bodies with an equal mass of M are attached by a pole with no mass with a length of L. The system is placed on a horizontal table and at first it is at rest. At t=0 a bullet with a mass of m hits the pole, as described in the picture. The collision is completely elastic...

Homework Statement A piece of lead of mass 1.5 kg is suspended from a light spring. A copper sphere of mass 2.5 kg is suspended by keans of a thread as attatched to the lead. The thread is then burnt. Calculate the acceleration of each mass at the instant the thread snaps Homework Equations...

I've heard the statement that by computing just the leading-order (tree level) diagrams of a process and then computing the derivative of this result with respect to the mass should correspond to the evaluation of the mass counter term diagrams. Can someone explain why this statement is...

From a frame of reference outside of a gravitational field, does the mass of an object near a gravitational field increase?

Hello, As many know, when an external force acts on a rigid body and the force's line of action does not pass through the body's center of mass ##c.m.##, the force will cause the body to both translate and rotate exactly about the ##c.m.##. Otherwise, the body will solely translate without...

Hello, Suppose that all stars in this galaxy were born in a single major-merger burst event about 10 Gyr ago If the luminosity in the B band (absolute magnitude in B-band is equal to -21.22) is dominated by stars of in the RG branch, with masses ##m \sim 1\,\text{L}_{\odot}## (within ##\sim...

<Moderator's note: Moved from a technical forum and thus no template.> Suppose that all stars in this galaxy were born in a single major-merger burst event about 10 Gyr ago. From this original burst, I want to compute the fraction of stellar mass still surviving as stars in the main sequence ...

Homework Statement A block of mass m having charge q placed on smooth horizontal table and is connected to a wall thorough an unstretched spring of constant k . A horizontal electric field E parallel to spring is switched on. Find the ampliture of the shm by the block. Homework Equations kx=...

I'm curious as to how the mass of a body affects the kind of atmosphere it can hold. I know that Earth tends to lose its lightest gases over time, which is one reason why helium doesn't build up in the atmosphere, whereas planets like Saturn and Jupiter have held on to lots and lots of hydrogen...

Homework Statement A closed funnel is 10 meters above a weighing scale. At t=0 we open the funnel. and 15kg of sand are coming out of it every second. The velocity of the sand when it comes out is 13m/s, directed downwards (towards the scale). At a certain moment the scale displays a value of...

Hello! In some of my college Physics practice problems, amplitude of a spring in Simple Harmonic Motion does not change with mass (for example, when the mass splits in 2 at equilibrium in a horizontal oscillator - see picture). But, in other problems, the Vmax of the oscillator remains constant...

If I fire an electron and positron bunch both in the same direction away from my experimental accelerator rest frame such that the electron bunch is fired with higher energy towards a "read end" collision with an already fired positron bunch and they collide a short distance away from the...

Last week I posted in General Physics some questions about what happens in a collapsing gas cloud, and I was advised that total angular momentum is conserved. I thought of asking for extra clarification here, as that seems really amazing -- I apologize for asking the same thing twice. I use a...

I have a question that appears elementary, but bizarre in its conclusion: A mass ##M## is accelerated by a spring of length ##L##, wave-speed ##v_p##, spring-constant ##K## and a constant force ##F## at the other end. As ##K## increases, the extension of the spring ##dx## decreases as does the...

In the cable-pulley system shown here, block A is moving upwards at a speed of 5m/s and block C is moving downwards at a speed of 2.5m/s. What is the speed of block B? (See attached picture) This seems easy, I just want to make sure I'm not crazy. If mass B moves downward some distance d...

Homework Statement There is a diagram of a rod with its center of mass labeled and a ball hanging down from it, attached by a string. Two torques are applied on either side. You are asked to find the mass of the ball and the mass of the rod. Homework Equations Torque = Force * Lever Arm *...

Any thoughts on this paper? https://arxiv.org/abs/1712.07962

Ugh ... I remember there was a reason ... but forgot what it was. So here's 3 bits of information gathered from dozens of sources, textbooks, official sites: Alpha particles are identical to Helium nuclei. Alpha particle mass = 4.001506 u helium-4 nuclei mass = 4.0026032 u OK, so ... why...

Homework Statement [/B] I got part A and B but in part c , but how to relate period to the equation in part b which is not similar to the cosine function of S.H.M . So i don't know how to obtain period from the equation PS: In part b ,I use mgsin(theta)=-kx and then divided by m Homework...

I recently read a short summary of Kepler 11 and the Kepler Mission. I understand that the orbital period of a planet is a function of its velocity and distance from the star, and the mass of the star will also factor in. Question: Is the mass of the planet also a factor? In other words, does a...

Given a large enough energy source (nuclear?)... can I build a rocket that creates its own reaction mass via electron-positron pair production, and then derive thrust by accelerating the charged particles out the back with a magnetic nozzle?

Homework Statement We have an Atwood machine like the picture below. one side (left) is a bucket full of water which has a hole on the bottom and the water is flowing with rate ##dm/dt = \alpha = const##. The initial mass of bucket with the water is ##m_0##. On the other side (right) we have a...

Hey, I've been having some trouble with my Lab report. After doing a titration of an unknown diprotic acid we had to find the molar mass of the acid and then find out which acid it is by comparing it to a list of given acids with molar masses. But when I run through the calculations my answer...

The ATLAS and CMS experiments at the Large Hadron Collider (LHC) recently released joint annual review papers regarding their measurements of the properties of the top quark and the Higgs boson, including their masses, respectively. The most recent mass measurement of the top quark are 172.51 ±...

Homework Statement Imagine two planets orbiting a star with orbits edge-on to the Earth. The peak Doppler shift for each 70 m/s, but one has a period of 7 days and the other has a period of 700 days. The star has a mass of one solar mass. (Assume 1 solar mass equals 2E+30 kg.) Q1: Calculate...

At sea level, we experience an external force pressing down on us at any given time which is equal to about 15 pounds per square inch. Pressure is defined as: ##P = \frac{Force}{Area}## where Force is equal to mass x acceleration. When we say that we experience this 15 pounds per square inch of...

Homework Statement Homework Equations pV = (m/Mr)RT (this is the formula given but I got the wrong answer using it) The Attempt at a Solution Mass = PV / RT R = 8.314 P1 x V2 / R x T1 M = 220 x 0.1 / 8.314 x 298 = 788.549kg Mass = 788.549kg P = 440000 V = 0.1 R = 8.314 T = 298...

Homework Statement Block A is traveling down an incline plane of 35 degrees at 2m/s. It's pulling a 4kg block with a pulley and rope. Coefficient of friction is.12. How heavy must block A be ? Homework Equations F=MA F = WsinΦ + μWcosΦ mgh = 1/2 mv^2 + WD to overcome friction Vf^2 = u^2 +...

Homework Statement I have the following questions as homeworks and I would like to get help. Here's some informations given to help us to answer : Photometry : U=11.60 B=11.16 V=10.20 Redshift : z= 0.00780 Central velocity dispersion : ##\sigma_{v}## = 210 km/s Introduction : The...

Homework Statement [/B] I have the following questions as homeworks and I would like to get help. Question 1) Give the formal expression of the total number density of galaxies. Why is this expressoin problematic in practice? Question 2) In practice one uses a numerical value for the number...

If the mass of the electron has been changing during the evolution of the universe, then the orbits of the electrons would also change, which will shift the light spectrum of each atom. Could this explain red shift of far galaxies, and the shift is not because the universe is expanding? Henry

This is not a homework. In Chapter 8: Central-Force Motion, in the Classical Dynamics of Particles and Systems book by Thornton and Marion, Fifth Edition, page 325, Problem 8-19, we are asked to calculate the mass of the planet Saturn. In the instructor's solution manual, the solution for this...

Homework Statement [please see attached photo] Homework Equations [please see attached photo] The Attempt at a Solution [please see attached photo] The issue for me starts with (but probably doesn't end with) replicating the velocity equation using the Conservation of Energy equations. Is...

Homework Statement a. At launch a rocket ship has a mass M. When it is launched from rest, it takes a time interval t1 to reach speed v1; at t = t2, its speed is v2. What is the average acceleration of the rocket (i) from the start to t1 and (ii) between t1 and t2? For now, I am taking...

Homework Statement A 100 g ball and a 250 g ball are connected by a 34-cm-long, massless, rigid rod. The balls rotate about their center of mass at 150 rpm . Homework EquationsThe Attempt at a Solution I solved by first getting the center of mass, then converting rpm into m/s I treated rigid...

Reduced mass can be defined as ##μ= \frac {m_1m_2} {m_1+m_2}## For ##m_1>>m_2##, ##μ_2≈m_2## How can we prove this ?

I have problem with an A2 physics question: A planet is orbiting a star at an average distance of 10^9 km. The period of its orbit is 500 Earth days. The gravitational constant is 6.67x10^-11 Nm^2kg^2. a) Calculation the mass of the star. b)Explain why you cannot determine the mass of the...

I am looking for articles or books that would clearly and succinctly state the open problem of and issues with computing hadron masses and spins in QCD from first principles, preferably in relation to the open problem of confinement and the general open problem of non-perturbative QCD. Any...

1. Homework Equations E=mc^2 Relativistic mass equation given in the question The first part of the question: I understand 200 MeV is the energy lost as it initially moves with 200MeV however is brought to rest and thus this total kinetic energy must have been transferred from the 'two...

If a photon does the 4 things listed below, why do we say it doesn’t have mass? I guess I’m asking if there’s a clear definition of mass. follows geodesics in spacetime (classically: accelerated in a grav field), curves spacetime (classically: creates a gravitational field), has momentum /...