Thursday, November 11, 2010

Chem Mid-Term Reveiw

2.The following length measurements were taken by students using several different measuring devices. Find the average of the measurements. Make sure that your answer has the correct number of sig figs. 10.05 cm, 10.1 cm,9.741cm, 10.6 cm, 10.5 cm. If the actual length were known to be 10.00, what would the percent error be?(Again be mindful of sig figs).


10.05 + 10.1 + 9.741 + 10.6 + 10.9 = 50.991 = 51.0


51.0 / 5 = 10. 2


(A.V. - E.V.) / A.V. x 100


(10 - 10.2) / 10 x 100


.2 / 10 x 100 


.02 x 100 


2%



*** To find the percent error the parenthesis should really be absolute value bars.