Answer:
F = 19600 N
Explanation:
After reading this interesting exercise, I think you are missing the diagram, but we are going to solve them assuming the height of the hill, point A of about h = 100m.
Let's start by using the concepts of energy, to find the speed at the bottom of the hill
Starting point. Point A highest part of the colima
     Em₀ = U = m g h
Final point. Flat part.
     [tex]Em_{f}[/tex] = k = ½ m v²
as they tell us that there is no friction, energy is conserved
    Em₀ = Em_{f}
    mgh = ½ m v²
    v = √2gh
let's calculate
    v = √ (2 9.8 100)
     v = 44.27 m / s
Now we can use the scientific expressions, when it stops its speed is zero
     v² = v₀² - 2 a x
     0 = v₀² - 2ax
     a = [tex]\frac{ v_{o}^2 }{2x}[/tex]
     a = [tex]\frac{ 44.27^{2} }{ 2 \ 50}[/tex]
     a = 19.6 m / s²
with this acceleration we use Newton's second law
      f = m a
      F = 1000 19.6
      F = 19600 N