Assuming no friction form air, how far will a dropped rock fall in 10 seconds

Given that

time (t) = 10 s ,

         (S) = ?

We know that  S = ut+ 1/2 a.t²  m

                         since free fall and no air friction,

                               a = g = 9.81 m/s² ; initial velocity u= 0

                         S = 0 + [1/2 × 9.81 ×10²]

                          S = 490.5 m

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2