So I calculated the answer to this problem and have an answer that looks like it is in the good range when compared to other people's answers online, however they have different weight measurements for their aluminum role, so here are my specific givens:Cost of 1 Roll of Aluminum: $1.59Area of 1 Roll of Aluminum: 6.96 metersWeight of 8inx 8insection of Roll: 2.7gMy answer is 1.57 x 10^-25Can somebody work this out and let me know if I am correct to three significant figuresIf not, do you know where I may have gone wrong? Thanks :)
you should be using dimensional analysislike this ($1.59 / roll) x (1 roll / 6.96m?) x (1m / 100cm)? x (2.54cm / 1in)? x (8in x 8in / 2.7g) x (26.98g / mol) x (1 mol / 6.022x10^23 atoms) $1.565x10^-25 / atom which you enter in your calculator as 1.59 / 6.96 / 100? x 2.54? x 8 x 8 / 27 x 26.98 / 6.022e23 andyou can easily see this is all mult / div so the sig figs in the final answer is the sig figs in the factor .with the least1.59 6.96 both have 3 sig figs 100 is exact .2.54 may or may not be exact (depending on who you're speaking with) but has at least 3 sig figs.8 has 1 sig fig .2.7g has 2 sig figs .26.98 6.022 both have 4 sig figs soyou tell mehow many sig figs should your report? alsorules of rounding (1) if the number to be rounded is followed by a number 5, round DOWN (2) if the number to be rounded is followed by a number 5, round UP (3) if the number to be rounded is followed by a 5 .(a)if the number to be rounded is even, round DOWN (b)if the number to be rounded is odd, round UP (4) all other numbers are ignored during rounding examples1.565 rounded to the 0.01's place 1.56rule 3(a) 1.575 rounded to the 0.01's place 1.58rule 3(b) why do we do this? we assume 50% of the numbers will be odd and 50% evenSo 50% of the time we round up .and 50% of the time we round downthat eliminates the .bias if we ALWAYS ROUND UP if the number is followed .by a 5right? 1.565 rounded up to 1.57 and 1.575 rounded .up to 1.58 is a 100% rounding up bias ! more examples 1.3659 rounded to 0.01 1.36rule (4) we ignore the 9 .why? because we assume the imprecise number is the 5 .and the 9 is therefore meaningless are you sure you measured the aluminum foil to +/- 1? did you mean to write 8.0 x 8.0?
Seek and Ye shall Find? Too many inconsistencies in all the Fairy Stories covering 9-11? Is American Public so Gullible to believe all this Crap they throw at you? Myth Huggers Unite eh? Put it all down to Conspiratorial Theories eh! Able Danger? And still swallow the Crap Governmental Stories? As you did on JFK, However the Truth has a Habit of Finding its way to the Top off all the Crap eh!
