G = 9.81N Using 10N is way to inaccurate. Also you didnt actualy tell me anything about G'forces as in coasters. You just told me that an object falling from a height of 50 metres accelerating at 10(wrong, should be 9.81) ms-2 will give you a resultant speed of 113.84 kmph. And you used such a (r) formula. Why not just use Newtons equations of motion?
Is this case i would use the third(or maybe forth, i forget) equation of motion which is
(V= final velocity, U=Inital velocity, T= Time, A= acceleration, X= displacement/distance)
v2 = u2 + 2ax (2 after a letter represents squared, cant superscript)
in this instance we can cancel out the inital velocuty as it is 0
Now you saying that you wish to know the final velocity of say a ball, dropped from 50m.
This is the method i was taught to work this out. First i would add VUTAX to the side, which is basicaly all the units you have be given and fill them in...like so
V= ?
U= 0 ms
T= ?
A= 9.81 (gravitational force)
X= 50 m
Now its a case of filling out the equation and seeing what we get
V2 = U2 + 2AX
V2 = (2x9.81) x 50m
V2 = 981mss (take note, to get V, you will need to half you answer)
V = 490.5ms
So we have worked out that by dropping a ball from rest at a height of 50m, with a uniform acceleration due to gravity of 9.81ms, a ball will be travelling, as it reaches the 50 metre mark, at 490.5 ms
This of course is not taking into account factors such as mass, weight, air resistance...so on and so force
http://www.crocodile-clips.com/absorb/A ... 10104.html
Good basic A level physics website with cool interactive stuff