1 PH - 2011 Experiment 1 : Uncertaint ies in Measurements Get you Stopwatch ( you can use your phone ) and E xcel spreadsheet ready We β ll take 30 measurements of t = time between two bounces of a ping pong ball dropped from a height of 1 meter 1) Average (mean) time between bounces t : ___________ 2) Standard deviation π π‘ : ___________ 3) Does about 2/3 of your data fall within one standard deviation of the mean? ______ 4) Error on the mean (i.e. Uncertainty o n the mean ) : ________ 5) Estimation of the systematic error: _______ 6) Write your measured value for the average time along with the total uncertaint y in the proper f ormat π‘ Μ Β± π₯π‘ (i.e . if you meas ured t Μ
= 0 79 s and a total uncertainty of π₯π‘ = 0 3 1 s , write down β t Μ
= 0 79 s Β± 0 3 1 s β , this is the proper way to communic at e the resu lts of your experiment ) : __________ 0 1 2 3 4 5 75 76 77 78 79 80 81 82 83 84 85 86 number of times measured time between bounces (1/100 s) Time measured between first and second bounce of a ping - pong ball