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Homework Help: Some Kinematics questions with cars and satallites

  1. Mar 18, 2008 #1
    Having difficulty with the followingCalculating this collision, as the standard equation does not apply, i don't think.

    Question 1:

    A 2000kg car travelling at 24 m/s EAST (x), collides with a 3600kg truck travelling at 10m/s SOUTH(y). What is there velocity immediately after impact.

    Question 2:

    An Earth Satellite travels in a circular orbit of radius 4 times the Earths radius. Calculate its acceleration in m/s^2

    Question 3:

    A satellite circles the Earth at an average altitude of 760km, with a period of 100 min. Calculate the mass of the Earth, if G = 6.67x10^-11 Nm^2/kg^2, and the radius of the Earth is 6.38x10^6m.

    Can you advise me the correct equation to use and directions, i'm lost. Please and thank you.

  2. jcsd
  3. Mar 19, 2008 #2


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    Homework Helper

    Welcome to PF!

    Hi Josh! Welcome to PF! :smile:

    By "standard equation", I take it you mean conservation of momentum in one dimension?

    It's ok - you just have two equations instead of one - conservation of momentum North, and conservation of momentum East! :smile:

    (btw, I suppose you're expected to use conservation of energy as well - but in practice, it wouldn't be conserved, because the vehicles would be deformed in the collision. :frown:)

    As to Questions 2 and 3: do you know a formula for the aceleration of something in a circle?
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