Physics

posted by .

A satellite of mass 220 kg is launched from a site on Earth's equator into an orbit at 200 km above the surface of Earth.
(a) Assuming a circular orbit, what is the orbital period of this satellite?
5310 s

(b) What is the satellite's speed in its orbit?
7790m/s

(c) What is the minimum energy necessary to place the satellite in orbit, assuming no air friction?

I was able to get a and b, but i don't know about c.

Thanks

  • Physics -

    You have to lift the body to orbit and then speed it up to orbit speed.
    m v^2/r = G m M/r^2 in orbit
    so (1/2)m v^2 = G m M/(2r) = Ke in orbit
    Change in Potential energy to lift it to orbit
    = G m M/(r-Rearth)

  • Physics -

    how do i get small r?

  • Physics -

    is it R_e + height?

  • Physics -

    Yes, earth radius + height

  • Physics -

    (6.67E-11*220*5.98E24)/(6.38E6+2.0E5)-(6.38E6)=
    1.33295653E10J

    Is this right? I want to make sure if this is right before I insert into the site.

  • Physics -

    both terms should be positive

  • Physics -

    What do you mean?

  • Physics -

    (6.67E-11*220*5.98E24)/[2(6.38E6+2.0E5)]
    note 2 in denominator
    + (6.67E-11*220*5.98E24) / 2^10^5

  • Physics -

    8.78*10^16 [ 1/1.32E7 + 1/2E5 ]

  • Physics -

    so is it 6770873457?

  • whoops error -

    Change in Potential energy to lift it to orbit
    = G m M [1/Rearth - 1/r ]

  • Physics -

    8.78*10^16 [ 1/1.32E7 + 1/6.38E6 - 1/6.58E6 ]

  • Physics -

    this is my last try....is it 6904053501?

  • Physics -

    7.07*10^9 Joules

  • Physics -

    We are close to each other. My arithmetic is failing, after bedtime.

  • Physics -

    Your professor must like arithmetic !

  • Physics -

    Yes, we are. Some of the problems are very difficult but thank you so much for your help. I really appreciate.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Math

    A satellite is launched into orbit 200 kilometers above the Earth.The orbital velocity of a satellite is given by the formula v=√GmE/r, where v is the velocity in meters per second, G is a given constant, mE is the mass of Earth, …
  2. Physics

    A satellite of mass 210 kg is launched from a site on Earth's equator into an orbit at 210 km above the surface of Earth. (a) Assuming a circular orbit, what is the orbital period of this satellite?
  3. physics

    Two Earth satellites, A and B, each of mass m, are to be launched into circular orbits about Earth's center. Satellite A is to orbit at an altitude of 7460 km. Satellite B is to orbit at an altitude of 20500 km. The radius of Earth …
  4. physics

    Two Earth satellites, A and B, each of mass m, are to be launched into circular orbits about Earth's center. Satellite A is to orbit at an altitude of 7460 km. Satellite B is to orbit at an altitude of 20500 km. The radius of Earth …
  5. Physics help PLZ!!

    Estimate the energy required from fuel to launch a 1465 kg satellite into orbit 1375 km above the Earth’s surface. Consider two cases: (a) the satellite is launched into an equatorial orbit from a point on the Earth’s equator, …
  6. physics

    Estimate the energy required from fuel to launch a 1465 kg satellite into orbit 1375 km above the Earth’s surface. Consider two cases: (a) the satellite is launched into an equatorial orbit from a point on the Earth’s equator, …
  7. physics

    A spy satellite was launched into a circular orbit with a height of 599 km above the surface of the Earth. Determine its orbital speed and period. (The mass of the Earth is 5.97 1024 kg, and the radius of the Earth is 6370 km.)
  8. Physics

    Some communication satellites are put into a circular geosynchronous orbit in which the satellite remains above a certain position on the earth's equator as it orbits. Such a satellite would always be in the same position in the sky …
  9. physics

    A satellite of mass 225 kg is launched from a site on Earth's equator into an orbit at 200 km above the surface of Earth. (The mass of the Earth is 5.98 1024 kg, and the radius of the Earth is 6.38 103 km.) (a) Assuming a circular …
  10. physics

    A satellite of mass 205 kg is launched from a site on Earth's equator into an orbit at 200 km above the surface of Earth. (a) Assuming a circular orbit, what is the orbital period of this satellite?

More Similar Questions