bag of sand with original weight 144 lb..

lifted in cnst rate & leaks in cnst rate ..

it was 1/2 weight (72 lb) when lifted up to 18ft ....

how to find work done this far ....

i did set the integral from 0-18

but cant find f(x)

any help pls.:)

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- January 31st 2009, 06:30 PMalex83leaky sandbagt
bag of sand with original weight 144 lb..

lifted in cnst rate & leaks in cnst rate ..

it was 1/2 weight (72 lb) when lifted up to 18ft ....

how to find work done this far ....

i did set the integral from 0-18

but cant find f(x)

any help pls.:)

- January 31st 2009, 06:45 PMahawk1
ill try and help lol.

f(o)=144 lbs, f(18)=72, therefore f(x)=144-(72/18)x. Next u take the integral of that and taking the integral from 0-18 u get 144x-2x^2 |0-18

giving u an answer of 1944 ftlbs.

im assuming u can take the intrgral by urself so i didnt explain that to much. does that answer ur question?

lol what book are u using, i had the same problem? - January 31st 2009, 06:50 PMalex83thanks 4 ur help tha was fast
thank u yes it does help ..

i was just looking 4 [f(o)=144 lbs, f(18)=72, therefore f(x)=144-(72/18)x]

i can deal with the integral :)

thanks again - January 31st 2009, 07:20 PMalex83book
im using THOMAS CALCULUS EARLY TRASCENDENTALS

i dont think its a great one cuz it doesnt explain alot

do u have any other book thats more helpful for calc

thnx - January 31st 2009, 08:10 PMahawk1