Mass Definition and 1000 Threads

(The answer from the markscheme is 26.7)

Hi everyone, I am thinking of solving it this way. Since Fc=mw^2r. and Fc=T. Then -dT=dmw^2r. where dm=m1(dx/l). and putting the lower at x=l the tension will be T=m2w^2l. Am I doing things right.

I believe they are the same?I think i am wrong.

I solved the last part of the previous question, But I got no idea how to start solving this question Like how the rope is being attached, is it attached to the inner disk or the outer one.

I want to express <m(x,y,z)> over a sphere of radius R in terms of $$<\rho(x,y,z)>$$ e.g $$<m>=\frac{\int_{sphere R}m(x,y,z)dv}{\int_{sphere}dv}$$ $$<m>=\frac{\int_{sphereR}(\int \rho(x,y,z)dv)dv}{\int_{sphere R}dv}$$

What would be the mass be of a planet traveling at 500,000 mph - if we assume the planet has the same mass as the Earth i.e. 5.9 sextillion tonnes?

In classical mechanics, the energy of a system of particles (say with 2 particles) in an external field is given by $$E=\frac{1}{2}m_1|\vec{v}_1|^2+\frac{1}{2}m_2|\vec{v}_2|^2+V(\vec{r}_1)+V(\vec{r}_2)+V'(|\vec{r}_2-\vec{r}_1|)$$ Where V is the potential energy of the external field, and V' is...

If an object's energy is proportional to its mass, how can a gram of antimatter produce more energy than 80 kilotons of TNT? Where does all this energy come from such a small amount of mass?Skip to 5:19 of the video where he says this: Please explain this in the most simplest way possible.

Could I please ask for help with the following: It's the final part I am having problems with. So at this point we know we have SHM of amplitude (5/4)L Now, using x = a cos(nt) ----- where we now know that n = sqrt(4g/L) we can find the time at which x has any value. So for exmaple, when...

In A.P. French's Special Relativity, the author said the following, As I understand, photons are massless, so I don't think the last equation above applies to photons, but then, when deriving it, he used an equation proper to photons (##E=pc##). So in which context is ##m=p/c## valid?

Is the mass that appears in E=mc2 the rest mass m0, or the relativistic mass γm0?

Atoms-to-mass conversion Step 1: First, convert the number of atoms to moles, then convert miles to grams Step 2: Second, use the inverse of the Avogadro’s number(moles to number of atoms) Are these the correct steps?

Background: My understanding is force and mass are two different things. Mass is how much matter is in a body Force is mass multiplied by an acceleration. Here on earth, that acceleration is 32.2 Ft/s2. Therefore, for the same mass, there can be different forces depending on the...

Please help please

My attempt to solve the first one. T-mg=ma T=m(g+a) TR = Iα I=(1/2)(M)(R^2) α=a/R TR=(1/2)(M)(R^2)(a/R) T=(1/2)Ma mg+ma=1/2Ma a=(2mg)/(M-2m) And... I got a wrong answer. As usual.

In an article its written, $$\Omega_{\nu} = \frac{\rho_{\nu}}{\rho_{crit}}=\frac{\sum m_{i,\nu}n_{i,\nu}}{\rho_{crit}} = \frac{\sum m_{\nu}}{93.14h^2eV}$$ Now I am trying to derive this for myself but I could not. Can someone help me ? So the values are, ##\rho_{crit} = 1.053 75 \times...

mass = 37.2 g AICI3 (given) number of ions = AI3+ Ions (unknown) number of ions = CI- Ions (unknown) mass = g/formula unit AICI3 (unknown) The ratio of AI3+ Ions to CI- Ions is 1:3 Molar Mass AICI3 (1 x 26.98 g/mol AI) + (3 x 35.45 g/mol CI) = 133.33 g/mol AICI3 molar mass = 133.33 g/mol...

Im trying to do some past exam papers. If i can get help with the method on how to solve and have correct formulas, it will help me. I) There is one formula in the notes to get mass flow rate: Heat lost by steam = Heat taken up by water GsHfg = (GwCpw)(change in temp) Gs x 2748 x 10x103 =...

This is the problem below that I have tried doing I ended up getting the mass of gas ejected to be 1.25kg from doing the following Would you say this is a reasonable value to get Thanks in advance!

Summary:: A block of mass m is dropped onto the top of a vertical spring whose force constant is k. If the block is released from a height h above the top of the spring, a) what is the maximum energy of the block? b) What is the maximum compression of the spring? c) At what compression is the...

Few days back, our college professor told us that if a photon were to have a finite mass, then the Coulomb potential between two stationary charges separated by a distance r would be strictly zero beyond some distance. He told us that it was due to the reason that photon is the elementary...

In the loop integral for the one-loop correction to the photon propagator in QED, the dominant term, after Wick rotation and angular averaging, has the form (omitting uninteresting factors) $$(1-2/d) e^2 \eta^{\mu\nu}\int_0^\infty \frac{p^{d+1}}{(p^2+\Delta)^2}dp,$$ where ##p## is the absolute...

how can i convert mass flow rate into molar flow rate using density of the gas.

I tried solving the differential equation by integrating both sides wrt t but this does not work out and I am doing something wrong. How do I integrate such an equation properly? d²x/dt² = -k²/x³ => dx/dt = -k²t/x³ => x = -k²t²/2x³ + d

So I'm playing around with some water rockets and I'm trying to figure out how fast the exhaust velocity of the water is. I've had an experimental approach using high fps camera to record and analyse (using tracker) the exhaust velocity. I'm using a 0,5 l soda bottle with 0,085 L ; 0,135 ; L...

I'm sorry but I can't even attempt this question since I'm pretty much clueless, I got the notes but I don't understand them.

I came across a question that states What mass would a neutrino need to still be relativistic today (T = 2.37K) ? So for a particle to be relativistic we need ##pc \gg mc^2## Well Neutrino was relativistic in the early universe, so I took the time when the neutrino decoupled which is...

Hello, and thank you again to anyone who can confirm if I have the right answer or who can give me some suggestions. This question felt like a bit of a surprise because we have not yet covered one where the mass of a planet was missing. Thus, my confidence in my work is low. Part b felt like a...

I started with calculating the Ep and Ek of the helicopter and got this: Epi = 490m Eki= (1/2)(400m) Epf = 12740m Ekf = (1/2)(1681m) I don't really know where to go from there. Do the unknown mass variables cancel out? I'm lost!

So I know that since we are ignoring the mass of the electron, and the proton starts at rest, the proton has no KE and the electron has no rest energy. So the initial total energy of the system would be rest energy of proton + KE of electron = 2GeV + .938GeV = 2.938 GeV and since energy is...

First I have to explain that this is not actually a homework problem. It is a problem I created to use in a sort of game. If I made a mistake, it tends to ball up the game. So I am looking for someone to double check my answer, and to point out any errors in my statement about physics. I prefer...

The first way to solve this is to just say, by conservation of momentum, that M_{0}v_{0}=(M_{0}+Apx)\frac{v_0}{2} where Apx is the mass of dust the rocket comes into contact with in a distance x. For the second method, by considering the change of momentum of the dust in 1 second, we know the...

Why doesn't the incline angle play a role in changing the ##m## component of this equation? ##T = 2π\sqrt{\frac{m}{k}}## FOR QUESTION 25, PART B: ANSWER:

Dark matter passes through everything, but is only influenced by gravity, so in the case of a neutron star, since dark matter doesn't interfere with ordinary matter, it can just pass through it, but neutrinos might be stopped by it's density, as neutrinos can just pass through stars almost as if...

Hello all After a lot of support from people like Dr.D, mfig and collinsmark I have finally understood the concept of Centriods and Centre of Mass. I am now trying to understand how a uniformally distributed force and a non uniformally distributed force acts on a shape. If I had an oddly...

Hi, Could I please ask for help regarding the following question. The book answer H = ( 3 - 3 sqrt(2)/4 ) L (natural length of string is L) Here is my diagram: The green level represents the unstretched string. The blue level is the string and mass in equilibrium. The purple level is the...

Homework Statement: Defining Centroid, Centre of Mass, Centre of Gravity for 2D/3Dshapes Homework Equations: Defining Centroid, Centre of Mass, Centre of Gravity for 2D/3Dshapes Hello all; I am trying to understand the terms:- - Centroid for a 2D shape and 3D shape - Centre of Mass for a 2D...

Hello all I was hoping someone could clear up the units & difference between Mass and Weight. I live in the UK. I weighed myself today on the scale and the scale told me that I weighed 95kg. What bothers me is that if:- Mass - Is the amount of "stuff" I am made from which is measured in kg...

Could I please ask for views on this question: I've answered the whole thing and agree with the answers given in the textbook. Here are those answers (where Y is the modulus of elasticity of the string = lamda in the question): Period of motion = 2 * PI * sqrt( ma/Y ) Speed passing through...

I am operating via finite differences. Say for example, I have this pipe that contains a fluid. I have the boundary condition at x = x1: k is the effective thermal conductivity of the fluid, T is the temperature of the fluid at any point x, hw is the wall heat transfer coefficient, and Tw is...

I'm currently looking at how fermion masses are produced via the Higgs mechanism in "An Introduction to Quantum Field Theory" by Peskin and Schroeder. It all makes a lot of sense and I've been fine with it so far, but I ended up getting stuck on something that's driving me nuts. I feel silly...

My Solution: For the displacement graph, the gradient is crucial to predict the behaviour of the displacement of the block through time. At 1: System is released - velocity is zero, considering forces acting on block, kx < mg, as block is observed to move downwards, and object is...

My Attempt So Far: 1) Drawing a diagram based on the question. Diagram 1: Pendulum Diagram Based On Question 2) List down pieces of information found in the question. θ1=53° θ2=37° m1=m1 m2=m1+50kg vi=0 3) Since 53°+37°=90°, I redraw another diagram making it into a right angle triangle in...

Hi ! This is my try: Is that correct ? Thanks

Hi, can anyone see if I have made an error in answering this simple question, my answer is not the one given in the textbook. Here's my diagram of the system in equilibrium. So the mass has dropped a distance x below the midpoint of PQ: So the forces balance as: T1 = g + T2 So, using...

Summary: I know that in order to keep inverted pendulum balanced when it leans forward, I should accelerate the bottom of it, but what is the force which is applied to center of mass of the pendulum with balances torque due to gravity? Is it inertial force? We assume that our inverted pendulum...

The Eddington luminosity gives a limit on the mass accretion rate of the black hole and therefore of the mass of the black hole. L_edd = 13*10^38 M/M_sun [erg s-1]. When I calculate from this I get that the maximum mass is M = 10^(-8)M_sun... which is impossible. Any ideas?

Is there any indication, such as through gravitational lensing, that dark matter has a low-mass compared to visible matter?

If there was no atmosphere and a point mass was released at the 45th parallel and able to counteract the centripetal force of gravity (hovering 10ft off the surface), how long would it take before it ended up at the equator.

I have attached the full answer in PDF file. I'm not sure about the answers. will really appreciate if they get checked