Mass Definition and 1000 Threads

Suppose there are 2 planets the size (diameter) of Jupiter. Both have the exact same mass. They are separated by a distance of about 10 times the diameter of the planet. They are both at rest. Now, will they start moving towards each other or stay in the same place? This is a sort of thought...

Homework Statement See attached diagram and statement of problem Homework Equations Conservation of momentum ... mv = MV + mv/2 mv/2 = MV V = mv/(2M) centripetal force...centripetal force equals weight at top of circle. MV^2/L = Mg V^2 = Lg V = (Lg)^.5 The Attempt at a Solution Set V = V...

Homework Statement Homework Equations xcxcxcxcxcxcxcxcxcxcxc[/B]The Attempt at a Solution My attempt: Let displacement of A be x m, Let displacement of B be y m, and Let displacement of C be z m. Step2: [/B]a+b+c+d=(a+x-y)+(b+x)+c+(d+z) 2x-y=-z Differentiating LHS and RHS components...

What would be the value of gravity on the surface of the Earth if its mass was twice as large and its radius half of what it is now?

The question is: The orange and blue cat are currently balanced on the see saw. The orange cat then eats a bird, which of the following could make the see saw balanced again? - I attached the picture that the question is referencing. And the possible answers are: A. Orange cat stays at same...

Homework Statement Find the centre of mass of a uniform hemispherical shell of inner radius a and outer radius b. Homework Equations ##r_{CoM} = \sum \frac{m\vec{r}}{m}## The Attempt at a Solution Using ##x(r,\theta,\phi)## for coordinates...

Homework Statement Consider a platform (mass: M) which horizontal surface AB s smoothly joined to vertical surface CD as shown in the figure below. Initially, the platform is fixed in place on a horizontal floor. A small object (mass: m) is placed on AB and given an initial speed of v in the...

I recently saw the movie “Man of Steel”. In Superman’s fight with Zod, Superman cuts (by melting) a steel I-beam, that Zod is about to hit him with, with a swipe of his heat vision. To melt steel that fast (under 3 seconds) requires a large temperature. My question is how can we calculate the...

Homework Statement https://imgur.com/jE8SMDR That's a drawing of the problem. I need to solve for the ? weight. Homework Equations not sure The Attempt at a Solution none, I don't want the answer, I just want the relevant equations. I haven't taken physics in a few years though (I'm out of...

Homework Statement an object of some mass, m, is accelerated upwards (from rest) off the surface off the Earth for some unknown time, t. At the end of this time, the object is traveling at some new speed, x. Derive the following formula. That is, show that no matter how much time the rocket...

Homework Statement A dog runs 480m in 28 seconds , we’ve to work out the mass of the dog Homework Equations F=ma [/B] M=f/a The Attempt at a Solution Really at a cross roads as every angle I work at this I need the mass of the dog to calculate the other components , a simple yes or no...

Homework Statement The proper length of spaceship A is 60.0m and the proper length of spaceship B is 120.0m. The proper mass of spaceship A is 15000 kg. An observer on Earth watches the two spaceships fly past at a constant speed and determines that they have the same length. If the speed of...

Homework Statement As on the paper below: Homework Equations Suvat? The Attempt at a Solution As on my paper a) I think I got the acceleration correct by measuring the angle, halving the angle to get the force upwards by each rope. Or is that the wrong answer? b) Should be half as it’s...

Homework Statement Homework EquationsThe Attempt at a Solution The force F exerted by the wall on the left end of the rope will make an angle 30° with the vertical . If we do the force balance , F sin30° = 20 Fcos30° = Mg This gives M = 2√3 Kg . This gives 3.5 Kg . But answer given is...

Homework Statement The mass of an electron is 9*10^-31kg. Find the charge in mass of a charged body if it loses 1 Coulomb of negative charge. Use your answer to explain why electricity was originally thought to be weight less. 1 coulomb = 6.642*10^18 elementary charges. Homework Equations...

Homework Statement Hello, I have a problem I don't want how to approach, it is a little weird. It is a problem of equilibrium (torque) The situation and my approach is in the picture I uploaded. A beam is supported by the blue structure. On the beam it is a person(100N) at a distance of 3m in...

Homework Statement We have a rod with length L and with the left end the rod is fixed to the ceiling in such a way it can swivel. As we can see from the picture (attached file) on right end two forces are acting on the rod: F and mg. The question is: How does the incline of the rod depend on...

Homework Statement A crane is moving two equally spaced masses to the roof. One box is 10kg and the other box is 20kg. As the plank tilts towards the 20kg box, at what angle will each box begin to slide? The coefficient of static friction is 0.4 Homework Equations Newton's second law, Fnet=ma...

Hello there, I am going to implement a numerical method to solve how much Mass of a fluid has gone out of an opened bottle. I am going to get h(t) with some sensors but I am not sure if this expression for Mass gone out "M" is correct. The area of the bottle at the up part. A1 The density of the...

Homework Statement The energy-band dispersion for a 3D crystal is given by $$E(\mathbf k) = E_0 - Acos(k_xa) - Bcos(k_yb) - Ccos(k_zc)$$ What is the value of the effective mass tensor at ## \mathbf k = 0 ##? Homework Equations The effective mass tensor is given by $$ \left( \frac{1}{m^*}...

Homework Statement A nuclear power generating station generates 3.0 x109 W of power. How much mass does the plant convert into energy each month (30 days)? Assume that the process is 100% efficient[/B] Homework Equations E = mc2 EJ = (Pw)( ts) The Attempt at a Solution First determine the...

Is there an astrophysical relationship between the how large a star's core gets and how large the star itself gets? Is it a simple linear percentage, or something more complex? For example, red dwarfs can fuse their entire hydrogen allocation, so the whole star is the core. But the Sun has a...

Homework Statement Let ##a > 0##. Find the mass of the "solid bowl" consisting of points inside the paraboloid ##z=a(x^2+y^2) \text { for } 0\leq z \leq H \text{. Assume a mass density of } \rho(x, y, z) = z##. Homework Equations ##x^2 + y^2 = z^2## The Attempt at a Solution [/B] mass = ##m...

Hello, can you please confirm this statement "Nuclear fusion does not require a minimum mass to occur (critical mass), which is instead a characteristic limit of fission. So you can make small fusion bombs as much as you want."? Thanks!

Homework Statement determine the center of mass of a thin plate of density 12 and whose shape is the triangle of vertices (1,0), (0,0), (1,1). Then, using the appropriate pappus theorem, calculate the volume of the solid obtained by rotating this region around the line x = -2. Homework...

Why is there an assumption that if neutrinos didn't have mass they would move at the speed of light? and how does the fact they oscillate prove they have mass?

What is effective mass? What is zero and infinite effective mass?

Homework Statement [/B] Homework EquationsThe Attempt at a Solution I think the two masses , inertial and gravitational are equivalent and because of this fact , the ratio of the two masses is one . The correct option should be 1) . But the answer given is 3) i.e A statement is true and R...

Hello When one calculates the speed of liberation of an object with respect to a star, one takes into account the force exerted by the star on the object. But not the force exerted by the object on the star. For small objects, this is valid. But what is the speed of release of a 1000 kg rocket...

Homework Statement How to determine variation of mean momentum of a nucleon with the mass number A of nucleus? Homework Equations R=R_0A^(1/3) The Attempt at a Solution Can't find a solution with elementary approach.

Its pretty tough to calculate the entire mass and weight of entire black hole.But how we will give a approximate value? How we will calculate its mass and weight? Could you list some stuffs that caught into the black hole? Has any scientist ever visited a black hole and collected data on it...

Hi everyone. I have some questions related to relativistic mass: Does atoms and molecules are affected by this relativistic effects? and does relativistic mass affects the way we weigh things? What I mean is; (and based on my limited knowledge of Special and General Relativity ) atoms an...

Homework Statement mass of pulley is 8 kg Homework Equations m1a=T m2g-T=m2a The Attempt at a Solution I solved question with neglecting mass of pulley but should I?

Homework Statement A solid disk of radius 23.4 cm and mass 1.45 kg is spinning at 43.1 radians per second. A solid cylinder of radius 12.1 cm and mass 3.33 kg is not spinning. The cylinder is dropped into the center of the spinning disk. After a short time friction has caused both objects to...

Homework Statement How (or if) I can calculate critical mass with the information I'm given? I have to write a criticality safety evaluation for an assignment. The assignment is about decomissioning a dissolver which was used to recover plutonium. On the contingencies section I need to apply...

No I'm not a particularly big person with a weight issue. Somebody asked me this question and I don't know the answer, but somebody here will. OK, it's now accepted that dark matter is everywhere in the Universe, it tends to clump with regular matter because all matter is subject to gravity...

How well is the transition between energy and mass understood? Energy can turn into matter and matter can turn into energy but what is actually happening between the two states? Imagining that matter just simply appears and disappears under an infinitesimal amount of time feels weird to me.

Homework Statement a small mass m hangs from a thing string can swing like a pendulum. You attach it above the window of your car as shown in the figure. When the car is at rest the string hangs vertically. What angle does the string make? a) when the car accelerates 1.20m/s^2 b)when the car...

Homework Statement [/B] A light rope passes over a light frictionless pulley attached to the ceiling. An object with a large mass is tied to one end and an object with a smaller mass is tied to the other end. Starting from rest the heavier object moves downward and the lighter object moves...

Homework Statement A point charge q1=15.00μC is held fixed in space. From a horizontal distance of 8.00 cm , a small sphere with mass 4.00×10−3kg and charge q2=+2.00μC is fired toward the fixed charge with an initial speed of 40.0 m/s . Gravity can be neglected. What is the acceleration of the...

Homework Statement 1.) A piece of bread (ε = 0.85) is being toasted in a toaster, as shown below. The heating element of the toaster consists of a wire 2 mm in diameter that is wound to approximate cylinders spaced 2 cm apart. This element acts as a blackbody. The housing for the toaster is...

Homework Statement A rod of length L and mass M has a nonuniform mass distribution. The linear mass density (mass per length) is λ=cx2, where x is measured from the center of the rod and c is a constant. Find the expression for c.Find the expression for the moment of inertia of the rod for...

Information Given:Zero, a hypothetical planet, has a mass of 4.2 x 1023 kg, a radius of 2.8 x 106 m, and no atmosphere. A 10 kg space probe is to be launched vertically from its surface. Question: (a) If the probe is launched with an initial kinetic energy of 5.0 x 107 J, what will be its...

Hi Everyone! Hope everyone is really enjoying pushing the Physics frontiers! Really need some help here. In the Electroweak sector of the Standard Model, it is apparently the case that the success of renormalisation to remove the Ultraviolet Divergence relies on the fact that at high energies...

Pretty self explanatory really. If a photon has a mass (1.67 * 10^-27 kg), and it travels at the speed of light, why does it's mass not increase to infinity?

Is the mass relative?

Hi. I am currently working on an assessed science experiment write-up. The experiment is about whether or not if mass of a pendulum bob affect the oscillation time for a simple pendulum. Obviously, the answer is no but I am struggling to write a concise and accurate explanation to why this is. I...

Please tell me what capital V and v mean in this equation. And how can we derive the second equation from the first one.

Homework Statement So this is more of a really vague conceptual question, I'm sorry if it doesn't really make sense. I'm in the stage of learning this where I don't quite understand things well enough to form a proper question. I'm a little bit confused about nodal networks in heat and mass...

Homework Statement Die average kinetic energy and impuls squared of a single molecule are: $$<E_{kin}>= 6.5*10^{-21} J$$ and $$<p^2> = 1.8*10^{-45} kg^2m^2s^{-2}$$ Which gas ist it? 3. The Attempt at a Solution ##\frac{m<v^2>}{2}=\frac{<p^2>}{2m}## ##\Leftrightarrow## ##\frac{<p^2>}{<v^2>} =...