physics

posted by .

We release an object of mass M at zero speed at a distance of 2*10^6 Km from the center of the earth. What is the speed at which the object hits the earth?
G=6.67*10^-11; g= 9.8 m/s; M=5.97*10^24;
r=6.3781*10^6
Suppose the mass of the object is M= 500 kg. What is the kinetic energy of this object when it hits the earth?
Thanks for your help.

  • physics -

    M= 5.97•10²⁴ kg
    m=500 kg
    r = 6.378•10⁶ m.
    R= 2• 0⁶ km= 2• 10⁹ m

    GmM/r-GmM/R = mv²/2
    GM(1/r -1/R) = v²/2
    v=sqrt{2GM(r-R)/rR}=
    =sqrt {2•6.67•10⁻¹¹• 5.97•10²⁴(2• 10⁹ - 6.3781•10⁶)/2• 10⁹•6.3781•10⁶}=
    =1.1•10⁴ m/s
    mv²/2 = 500•(1.1•10⁴)²/23.025 •10¹º J

  • physics -

    Thanks Elena for your help. I have been having trouble with some of these equations.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    An object in the vacuum of space orbits the earth at a fixed speed in a circular orbit several hundred miles above the earth. What can we conclude about the reaction force?
  2. physics

    An object in the vacuum of space orbits the earth at a fixed speed in a circular orbit several hundred miles above the earth. What can we conclude about the reaction force?
  3. physics

    An object in the vacuum of space orbits the earth at a fixed speed in a circular orbit several hundred miles above the earth. What can we conclude about the reaction force?
  4. physics

    An object in the vacuum of space orbits the earth at a fixed speed in a circular orbit several hundred miles above the earth. What can we conclude about the reaction force?
  5. physics

    An object in the vacuum of space orbits the earth at a fixed speed in a circular orbit several hundred miles above the earth. What can we conclude about the reaction force?
  6. physics

    An object in the vacuum of space orbits the earth at a fixed speed in a circular orbit several hundred miles above the earth. What can we conclude about the reaction force?
  7. Physics

    The Earth has an angular speed of 7.272·10-5 rad/s in its rotation. Find the new angular speed if an asteroid (m = 3.45·1022 kg) hits the Earth while traveling at a speed of 4.41·103 m/s (assume the asteroid is a point mass compared …
  8. physics

    Imagine a frictionless perfectly straight tunnel which runs from Boston (USA) to Delhi (India). We release (at zero speed) an object in the tunnel in Boston. Assume that the Earth is a perfect sphere with radius 6.4*10^3 km, with a …
  9. physics

    Imagine a frictionless perfectly straight tunnel which runs from Boston (USA) to Delhi (India). We release (at zero speed) an object in the tunnel in Boston. Assume that the Earth is a perfect sphere with radius 6.4*10^3 km, with a …
  10. phy 231

    It takes 23 hours 56 minutes and 4 seconds for the earth to make one revolution (mean sidereal day). a.What is the angular speed of the earth?

More Similar Questions