Gravitational Definition and 1000 Threads

Everything that has mass , posseses gravitational pull. We as humans do have mass, and thus posses gravitational pull too ? If so , do we posses tiny amount of gravitational pull ?

This is an excerpt from "Introduction to Mechanics" by Kleppner and Kolenkow: "The reason why gravitational force vanishes inside a spherical shell can be seen by a simple argument due to Newton. Consider the two small mass elements marked out by a conical surface with its apex at ##m##. The...

Things space contract and time dilate in SR. And also things space contract and time dilate near heavy objects in GR, right? Particles are accelerated towards heavy objects in GR. My question is does the the acceleration due to gravity produce a frame of reference equal to some speed which...

Homework Statement For a satellite of mass ##m_s## in a circular orbit of radius ##r_s## around the Earth, determine its kinetic energy K. Homework Equations ## K = \frac {1}{2}mv^2 ## Gravitational potential energy ## U(r) = - \frac {GmM_E}{r}## The Attempt at a Solution My answer is ## K...

Im looking for some easy equotation which would help me to make graph of time dilation depending on gravity expressed not in relation to Schwarzschild radius but simply and directly to gravitational acceleration. I would like to get some easy graph similar to this...

Hi! Could someone please explain the difference between gravitational and inertial mass? And how are they equal? Thank you!

Homework Statement A 500 kg satellite experiences a gravitational force of 3000 N, while moving in a circular orbit around Earth. A) Find the radius of the orbit B) Find the speed of the satellite C) Find the period of the orbit I found this set of questions a bit trickier, although am...

A large spherical planet of radius R made of a material of density d, has a spherical cavity of radius R/2, with center of cavity a distance R/2 from the centre of the planet. Find the gravitational Force on a small mass m at the centre of the cavity

I know the total energy of universe is zero cause of matter energy (E=mc2) and gravitational potantial energy. But If I try to calculate it gets crazy things: Lets think universe made up only two particles and their mass call m and equal than 2mc2=m2G/r 2c2=mG/r r=mG/2c2 so...

Homework Statement [/B] Calculate the gravitational potential energy of the interacting pair of the Earth and a 23kg block sitting on the surface of the Earth. You would need to supply the absolute value of this result to move the block to a location very far from the Earth (actually, you...

Homework Statement [/B] 1)Which describes the 1D gravitational force in this figure. (+x is to the right.) a)Something else. b)Fgrav=−GMmx2 c)Fgrav=+GMmx22)In moving the little mass m from x1 to infinity the force of gravity does _____________ work. a) positive b) negative c) no I added an...

Homework Statement Homework EquationsThe Attempt at a Solution I can't understand what is ɛ in this problem, and why should we adopt it. Could you explain me please?

Imagine a massive object emitting photons of various frequencies. Because the object is massive, it will exert gravitational acceleration on those photons. Because the energy of a photon is proportional to its frequency, it seems that higher-frequency photons will experience a higher magnitude...

considering the Earth as a sphere, at the centre of the earth, by the equation F = G*m1*m2/r^2 , the gravitational pull experienced would be infinite . so assuming that we built a tunnel from 2 ends of the Earth through the centre, and a person jumps into the tunnel. till the centre of the...

The usual calculations for gravitational waves linearize the GR equations around the background solution of flat space time ( g = Minkowski metric matrix ) empty of matter and energy ( T = 0 ) What happens in cosmology, when one must linearize the GR equations about the FRW metric matrix with...

I'm a complete and utter layman here, so please forgive any misunderstandings, but I'm just curious about something and wonder if people could say some words on the subject. So as we understand it, the universe is constantly expanding, but expanding at an accelerated rate, so wouldn't this have...

Can someone help me with this question, Calculate the force of gravity on a 70-kg astronaut 2.0 Earth radii from the centre of Earth.

Hello PPer's, I have been considering the effect to which electromagnetic radiation emitted from stars might play in the gravitational coalescence of galaxies. Surrounding every galaxy there must be a halo of electromagnetic radiation streaming outwards at the speed of light which diminishes...

Hi, According to Newton, F= (GM¹M₂)/r² Einstein proved that light bends around massive bodies, due to gravity. (because space bends around these bodies) Mass of light = zero, but its being affected by gravity. So, is Newton's equation not universal?

If we use one gravitational field in GR and try to desribe it, we will see that from the perspective of the observer on the centre of mass of the object the clock on the hovering observer (farther away from the gravitational field) runs faster, while from the hovering observer's perspective the...

Homework Statement Mass M is distributed uniformly along a line of length 2L. A particle of mass m is at a point that is a distance a above the center of the line on it's perpendicular bisector. For the gravitational force that the line exerts on the particle. calculate the components...

1. The problem statement, all variables and given/known dat Three solid spheres of lead, each of mass 9.8 kg, are located at three corners of a square with side lengths of 50 cm. A small object is released at the forth corner. Considering only the gravitational forces among the four objects...

Suppose that everything in the Universe - the radius of the sun, the astronomical units, radius of atoms, and everything else were to expand proportionately during the same period of time. This would mean also that the ratio of the time period of the various planets around the sun, and all local...

I'm trying to understand on how people came up with gravitational law i.e. observations, experiments, theories etc. I have read a bit but there are some blanks that I cannot fill. I need some help regarding that. It seems that people like Hooke, Newton already knew that there exists...

In practice I’ve found that a valid gravitational model of orbiting bodies only works when the force is computed with only the other mass and not both masses. Thus, the original equation does not work but the modified one does. Is using one mass ok or am I doing something wrong? thanks. [also...

Around massive bodies, light bends so that we can see multiple images of the same object, such as multiple images of the same galaxy behind the massive body. I know this seems kind of a dim question, but how can we know that the similar images we pick up are light rays from the same object that...

If you view free fall as an inertial frame and therefore items at "rest" on the Earth's surface are accelerating away from the centre of mass I do not understand how energy is conserved. Taking this view, relative to the free fall frame the items will be gaining velocity which implies that the...

If light was being produced in an intense gravity field, would the light be of higher or lower frequency/energy to a distant observer? I understand that the light escaping the gravitational field would be red shifted, but that is not what I'm asking. I'm asking about the relativistic effects on...

Homework Statement 1)Find the gravitational force between then sun (2*10^30 kg) and the Earth (5.97*10^24 kg). Earths distance from the sun is 1.5 * 10^11m. 2) find the distance between a 5 kg object and a 10kg object if their gravitational force is 1*10^-4N. Homework Equations Fg=...

We went over Coulomb's law today, which can be stated as (1/ε0)(1/(4πr2))(|q1q2|) This equation is very similar to Newton's law of gravitation, but it contains 1/4pir^2. This makes sense, because the electric force is being diluted over the surface of a sphere. Is 1/(4πr2) built into G as well?

How long does the gravitational collapse of a giant molecular cloud take? The charged particles acquire quite a huge speed before hitting each other with an impact strong enough to cause nuclear forces take over. This implies that the process of acceleration should take a long time, since...

√Homework Statement Show that the gravitational field due to thin uniform circular plate of radius a at point distant R from center and on the axis passing through the center and perpendicular to the plane of the plate is given by E= -2πGρ[1-R/(a^2+R^2)^1/2] Homework Equations F= GMm/r^2...

Homework Statement What is the magnitude of the net gravitational force on the m2=5kg mass? Assume m1=25kg and m3=15kg. https://session.masteringphysics.com/problemAsset/1383524/6/13_P28.png Homework Equations F=GMm/r^2 The Attempt at a Solution First I find the angle between m1 and m2 which...

Homework Statement Two bags, each containing ten oranges of equal mass, are hung 4.0 m apart. Describe two situations, one involving mass and the other involving separation distance, that would quadruple the gravitational force exerted by one bag on the other. Explain your answer...

Homework Statement A 2000-kg elevator with broken cables in a test rig is falling at when it contacts a cushioning spring at the bottom of the shaft. The spring is intended to stop the elevator, compressing 2.00 m as it does so. During the motion a safety clamp applies a constant 17,000-N...

For centuries we have been using the gravitational potential energy of water courses by building watermills and dams with hydroelectric plants. The weather does the job of bringing the water back 'upstairs' for free so conceptually that's a wonderful energy source. The problem is (I guess) that...

Homework Statement Homework EquationsThe Attempt at a Solution For a), I initially tried to consider the component of the gravitational force of the moon acting normally to the Earth's surface. This would be F=F_0 cos(theta) where theta is the angle between a horizontal line going through A...

Hi, as an engineer i don't have much formal training in theoretical physics so bare with me. As most of you know, we can only understand 4% of our universe with the current models we have. The rest of the 96% is dark matter and dark energy (23% and 73%, respectively). Could these unexplained...

Homework Statement Part A: Derive an expression for the energy needed to launch an object from the surface of Earth to a height h above the surface. Part B: Ignoring Earth's rotation, how much energy is needed to get the same object into orbit at height h? Express your answer in terms of...

I kind of have a stupid question. How much more massive would the Earth have to be for the average person to weigh about 50 more pounds? How much bigger could the Earth's diameter be? Thanks.

Is the height in the formula the vertical distance from the bottom to the center of gravity of object, or is it just the vertical distance from the bottom to the very top of the object. I mean.. If there is a sphere with mass m and radius r and placed at height h, what is its potential...

I'm curious as to what he did to figure it out *Newton, sorry

I am trying to derive the gravitational red shift effect but I think I am going about it all wrong. Specifically, I want to derive the change in frequency/ wavelength when a photon moves away from the surface of a star mass M and radius R. So I tried to use relativistic mass of the photon and I...

I want to ask a question about science/physics. To me and my level of education, this has not been answered, though I am sure there is someone out there that can provide the answer. It regards something I have been pondering due to gravitational time dilation (and space dilation I suppose, if...

Homework Statement a) A mass ##m##, initially at rest, is released from infinity, and is attracted towards a planet of mass ##M##, displacing towards it in a direction parallel to the gravitational field lines present between the masses. Assuming that the only force acting on ##m## is the...

A 20 kg mass is situated 4m above the Earth's surface Taking g as 10 m/s2. What are the gravitational field strength and gravitational force acting on the mass? Am I wrong when I say that because the height of the mass ( which is 4m) is too little comparing with the radius of the Earth so that...

Homework Statement A broken spaceship is located h=10 km above the center of a large circular thin sheet of unknown dust. The sheet has a radius of R=106 km and a density of σ = 7*1011 kg/m2. The spaceship and the dust attract each other due to the gravitational force. a) Find the initial...

In this case the height of the fall is far to high above Earth to be use PE=mgh. So I'm trying to integrate the inverse square gravitational force over distance. ##\int \frac{GmM_e}{r^2}dr## So I'm confused with respect to another object, specifically the moon, if the max height of the fall...

HEy what is uniform and non-uniform gravitational field...

This paper, http://arxiv.org/abs/1501.00996, proposes using atomic clocks for gravitational wave detection. It sounds similar to other ideas involving pulsar timing experiments. The twist here is utilizing satellites to provide a wide base for improved sensitivity. Sounds like an inexpensive...