Math Induction Problem

[lovemake1]

1. The problem statement, all variables and given/known data

Suppose that n identical planks, each of length 1 metre, are stacked flat on top of each other, with each one shifted a little further to the right, creating an ever-larger overhang. Prove the maximum span of this overhang is Fn = 1/2 [1 +1/2 + 1/3 + 1/4 + ... + 1/(n-1) ] using induction.


2. Relevant equations

for two objects of masses m1, m2 and distance r1 and r2 (measured from a fixed location):

R = (m1*r1 + m2*r2)/(m1 + m2)


3. The attempt at a solution

I've tried this problem for 3 days but I'm still not able to come up with an equation for Fn.
so that Fn = the right side..
for example i would need an equation of Fn to check the base case and prove using induction step.

If someone can give me the beginning of the equation or even a big hint would be greatly apprecicated. I need to put an end to this problem soon..

[Berko]

Well, the way induction works is you prove it for the first case (in this case when n=2) and then as an entirely different step, you assume it is true for a random n and then show it is also true for the n+1' case.