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Homework Help: What is the magnitude of the net force acting on the kayak?

  1. Oct 6, 2009 #1
    neutron star has a mass of 2.0 x 10^30 kg, and a radius of 5.0 x 10^3 m
    suppose an object falls from rest near the surface of such a star. how fast would it be moving after it had fallen a distance of 0.010 m? (gravity constant over star, and star is not rotating)


    a person in a kayak starts paddling, and it accelerates from 0 to 0.60 in a distance of 0.41 m if combined mass of person and kayak is 73 kg what is the magnitude of the net force acting on the kayak?
  2. jcsd
  3. Oct 6, 2009 #2
    Please show some work. The first question requires the equation for gravitational force, the second asks you to use the definition of force.
  4. Oct 6, 2009 #3
    my prof wrote down some equations for the first one

    Fg = G(mMn/Rn^2 = m(GMn/ Rn^2)

    and then

    Fg = ma

    but im not sure about the second one....thats mainly why im asking.. is because i dont know how to do it....
  5. Oct 6, 2009 #4
    Both are correct. They allow you to determine the acceleration a from knowledge of the other variables in the first equation.
  6. Oct 6, 2009 #5
    okay.. but still don't know how to solve it..
  7. Oct 6, 2009 #6
    k i think i get the second one.. but the neutron star one still is a no go
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