Gravitational field Definition and 366 Threads

  1. M

    Escape Velocity Calculation for Orbiting Satellite

    I am having some difficulty with this question: A satellite is in orbit around Earth at an altitude of 3700 km. How much must its speed increase, in km/h, to escape the Earth's force of gravity? I'm stumped. Please help
  2. G

    Gravitational field strength formula

    Q: "The Earths radius is 6700km. Show that the magnitude of the gravitational field strength at a height of 350km above the Earth's surface is about 9 N/kg" I got the mass of the Earth which is 5.98E 24 G the constant = 6.67E -11 Formula : g= GM/r² , i can't seem to get 9, am I supposed...
  3. Y

    Gravitational field, two body problem, lagrangian points

    I want to calculate the lagrangian points of the gravitational field in a 2-body problem. i want to superpose the two gravitational fields of the bodys and after that transform them into a rotating system which has the same angular velocity as the 2-body system does have. from this...
  4. U

    Solving Gravitational Field: What Did I Do Wrong?

    the question is http://home.earthlink.net/~urban-xrisis/phy.jpg g=\frac{GM}{x^2} x=\sqrt{r^2+a^2} g=\frac{GM}{(\sqrt{r^2+a^2})^2} g=\frac{GM}{r^2+a^2} since there are 2 masses... g=2 \frac{GM}{r^2+a^2} my book's answer is: g=\frac{2MGr}{(r^2+a^2)^{3/2}} what did I do wrong?
  5. A

    Gravitational field due to a cylinder

    Calculate the gravitational field due to a homogeneous cylinder at an exterior point on the axis of the cylinder. Perform the calculation by computing the force directly. I'm not sure if I did this right, here's what I did z = distance from point to center of cylinder r = distance from...
  6. T

    Does a massive object interact with its own gravitational field?

    Does an electrically charged particle's own electric field affect its own path in space? i.e., does the particle's electrical nature interact with its own field? Does a massive object interact with its own gravitational field?
  7. G

    How do you calculate time dilation in a gravitational field

    How do you calculate time dilation in a gravitational field. I already know SR time dilation equations, t=t*sqr(1-v^2/c^2), I have even designed a software in VB to calculate it. But I do not know how to calculate time dilation in General Relativity. Can someone please tell me? I am trying...
  8. A

    Two masses and a Gravitational field

    A point mass of 3.8kg is on the x-axis at x=8.2 and an equal point mass is on the y-axis at y=5.9. What is the magnitude of the gravitational field from these two masses at the origin? Well for this problem I tried using the equation F= G m1 m2/ r^2 for r I added 8.2 and 5.9 for G I...
  9. P

    Far Gravitational field of a moving mass

    I've been trying to figure this one out for a while, I could use a bit of help. I think I'm getting close. If we consider the metric (1+2*m/R)*(dx^2+dy^2+dz^2) + (-1+2*m/R) dt^2, we have the metric of the nearly-Newtonian far-field of a body with mass m. If the mass isn't moving, we...
  10. A

    Physics Help : gravitational field

    Two stars, masses 10^20kg and 2* 10^20kg respectively, rotate about their common centre of mass with an angular speed of w. Assuming that the only force on a star is the mutual gravitational force between then, calculate w. Distance = 10^6km and that G= 6.7*10^-11Nm^2/kg^2
  11. L

    Gravitational Forces on the Edge of a Disk

    What if we had a large and massive object shaped like a disc (look at the attachment) and we would walk on its edge. If we would step on the flat part what would happen? P.S. I am going on holidays for a fe days so i won't be abel to check out your answers very soon.
  12. T

    Calculate the gravitational field of a object

    how do you calculate the gravitational field of a object e.g black hole (does it refer to its density and mass?
  13. M

    Gravitational field in a hollow sphere

    Can someone please give me a qualitative justification for the gravitational field inside a uniform hollow sphere being zero? I'm having a lot of trouble understanding this. Prof. said (in class) not to worry about the higher order polynomials involved, just be concerned with it...
  14. B

    Gravitational field of globular clusters ?

    what does the gravitational field at the center of a globular cluster look like? it doesn't look as though there is any angular momentum - is there a 'center' of gravity inside? a black hole?
  15. I

    Gravitational Field Strength of Sun vs Moon at Earth

    I was just wondering. How come the gravitational field strength of the sun is much larger than the gravitational field strength of the moon at when you calculate both values at Earth's position?
  16. Z

    Geodesics inside a spinning ball of the gravitational field matter

    The linear velocity of rotation of a spinning ball of the gravitational field matter (gfm) is faster at its edge than in its central part. According to Einstein's theory of the spinning disk, the spacetime curvature at the edge of the gfm ball is larger than that in the central part; and...
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