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What is the magnitude of the net force acting on the kayak?

  • #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)


and

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?
 

Answers and Replies

  • #2
1,013
65
Please show some work. The first question requires the equation for gravitational force, the second asks you to use the definition of force.
 
  • #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....
 
  • #4
1,013
65
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....
Both are correct. They allow you to determine the acceleration a from knowledge of the other variables in the first equation.
 
  • #5
okay.. but still don't know how to solve it..
 
  • #6
k i think i get the second one.. but the neutron star one still is a no go
 

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