IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: hols on May 12, 2010, 08:40:35 am

Title: URGENT QUESTION! No time left please guys ..
Post by: hols on May 12, 2010, 08:40:35 am
Physics May/June 2009 paper 3B
Section B, Question 6

It says (for the people who dont have it):

An engineer carried out an investigation to determine the Young modulus of a sample of a material.

(b) The engineer obtained three sets of data. The values for the Young modulus were 14.2, 14.7 and 15.1 GPa.

Determine the average value and state its uncertainty.
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The average value is 14.7, but what's the uncertainty ? And please elaborate how did you calculate it?
Title: Re: URGENT QUESTION! No time left please guys ..
Post by: T.Q on May 12, 2010, 08:51:25 am
range /2

(max value - min value)/2

(15.1-14.2)/2=0.45

and the uncertainty always take it to one significant figure

so uncertainty = +-0.5 
Title: Re: URGENT QUESTION! No time left please guys ..
Post by: abuelzouz on May 12, 2010, 09:10:15 am
wt about last hour revision?
Title: Re: URGENT QUESTION! No time left please guys ..
Post by: Q80BOY on May 12, 2010, 09:15:29 am
don't do last hour revision .. chill out .. grab a bite .. head to the exam refreshed and relaxed ;)

best of luck!!  :)
Title: Re: URGENT QUESTION! No time left please guys ..
Post by: hols on May 12, 2010, 09:15:49 am
Thank you so much ! +rep
Title: Re: URGENT QUESTION! No time left please guys ..
Post by: abuelzouz on May 12, 2010, 09:16:47 am
yea i knw but i just want 2 make sure i covered everything..

wt did u study?
Title: Re: URGENT QUESTION! No time left please guys ..
Post by: halosh92 on May 12, 2010, 06:30:50 pm
nov 2009
paper 1 cie physics
Q6
Q21
Q26
Q27
Q29
thxx alooot
By the way does anyone think that this paper is hard or is it just me??
:S :-\