Recent content by xyd

  1. X

    Spacecraft launched from the earth

    OK, my answer has been proved right. I was quite nervous as it was already the final attempt. Thanks so much for your help, gneill and supratim1!
  2. X

    Spacecraft launched from the earth

    Get it! Thank you.
  3. X

    Spacecraft launched from the earth

    One more question, is the kinetic energy 0 at infinity??
  4. X

    Spacecraft launched from the earth

    Could I do the question this way: Suppose: - Ks is the minimum kinetic energy required to escape (relative to the mass center of the sun); - Ke is the minimum kinetic energy required to escape (relative to the mass center of the earth); - Ps is the potential energy from the sun - Pe is...
  5. X

    Spacecraft launched from the earth

    Yes, it makes sense. I would try this way. Thank you. In addition, I believe the rotation of the Earth should not be considered as what the question mentioned "Take into consideration the gravitational effects of both the Earth and the sun, and include the effects of the Earth's orbital speed"...
  6. X

    Spacecraft launched from the earth

    Well... yes. Actually, I tried it once, but I still failed. However, I really found the velocity escape from Sun is really much larger. Hence, could I make such a conclusion: the velocity of the ship relative to the Sun is the escape velocity from the Sun?? Whatever, thanks a lot!
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    Spacecraft launched from the earth

    I am sorry that I did not remember the detail of attempt clearly, but PLEASE PLEASE HELP ME!
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    Spacecraft launched from the earth

    First, I am sorry that I did not show my attempt clearly. This is my first time to post a homework thread. Sorry again! And then here are my attempt. First of all, I take: mass of Sun: M = 1.99 x 1030 kg mass of Earth: m = 5.97 x 1024 kg orbit radius of the Earth: 1.50 x 1011 m Then...
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    Spacecraft launched from the earth

    1. A spacecraft is to be launched from the surface of the Earth so that it will escape from the solar system altogether. Find the speed relative to the center of the Earth with which the spacecraft must be launched. Take into consideration the gravitational effects of both the Earth and...
  10. X

    What does the circle in the integral sign signify?

    http://answers.yahoo.com/question/index?qid=20090115082449AAAKyUN
  11. X

    Object floating on the surface of water

    Hey, why no one seems interested in this question?
  12. X

    Object floating on the surface of water

    How to use a function f[x,y,z] to describe the shape of water surface when a tiny object is floating on it based on surface tension ONLY? Assume there is a tiny object floating on the water surface because of the surface tension, then the water surface will be deformed obviously. So how can...
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