Acceleration Problem: Solve for U & A

[kazuya99]

Homework Statement

I have been given a set of results to analyse, regarding acceleration of a free fall object in a piece of paper, (100g mass, 10cm card) falling through a light gate at different heights, i am having problems with working out the acceleration using formulae.
Distance from gate = 0.02m
Time = 0.163 seconds.
U = 0 i presume..or maybe not(part of my problem)
S = 0.1 (the length of the card)

Homework Equations

s = ut + 1/2at(squared)

The Attempt at a Solution

I have got 9.15 once but i think it was a coincedence.

 

[chaoseverlasting]

For the lighter objects, you have to take the air resisatance into account. The answer you got correct, would probably have been for a heavier object cause the air resistance is negligible for them.