Newtonian gravity Definition and 59 Threads

I've recently been looking at the way in which pressure terms contribute to the Komar expression for the total energy in GR and I've been trying to understand the Newtonian equivalent. I found something which surprised me, and I'm wondering if it's well-known: If you take a couple of masses...

Before I inundate you with various elementary problems I'm facing, I need help with the concept. Fgrav=(GMm)/(r^2) So Fgrav is in units of Newtons, correct? How would one convert that to m/s?

Homework Statement The problem is: Consider a tunnel that connects any two points A and B on the spherical Earth (assuming constant density). The tunnel is a vacuum, and the train traveling through the tunnel is traveling on a frictionless track with no engine (i.e. it is just falling through...

I've only just completed high school, but I have a decent grasp on basic undergrad maths/physics. After hours and hours of paper and mental calculations, I still can't see a way of solving Newton's law of gravitation for the path of a body given inital position/velocity i.e. the second order...

how would you describe Newtonian gravity as a vector field?

Looking for help interpreting a proof of G.R. please. . . One of the earliest proofs of G.R. was the deflection of light by a gravitational field, first shown in 1919 during a solar eclipse. I think Einstein predicted approximately 1.7 seconds of arc deflection during that eclipse. But...

1-dimensional problem in Newtonian gravity- HELP! The problem is this: Given sun of mass M and a body of mass m (M>>m) a distance r from the sun, find the time for the body to 'fall' into the sun (initially ignoring the radius of the sun). Our first equation is therefore \frac...

The problem is this: Given sun of mass M and a body of mass m (M>>m) a distance r from the sun, find the time for the body to 'fall' into the sun (initially ignoring the radius of the sun). Our first equation is therefore \frac {d^2r}{dt^2} = \ddot{r} = \frac {GM}{r^2} . I am able to...

The problem is this: Given sun of mass M and a body of mass m (M>>m) a distance r from the sun, find the time for the body to 'fall' into the sun (initially ignoring the radius of the sun). Our first equation is therefore \ddot{r} = \frac {GM}{r^2} . I am able to integrate this...