volumes help (1 Viewer)

[randhi]

hey,
i was wondering if some could please explain to me what the actual concept of volume by cylinderical shells is??
it is taking the actual shell of what ever shape or is it the just the cylinder shape. if so, how does that work when your trying to find the volume of a doughnuts. the circle has a centre origin.
i just don't get it!!

 

[redslert]

you want people to put it into word?! HARD

hmmm

it is basically taking shells, but these shells have really small thickness, hmmmm imagine a roll of toilet paper..yeh, each shell really thin, and then you just take the sum of many of the shells together to get the volume!

for doughnuts, wouldn't it be easiler to use discs?! which works the same way....really thin discs added them together


the integeration sign:
/
|
/
it's shaped in an S because it stands for "sum"....

hope that helps

 

[randhi]

lol, thanks that helped.
yeh it is easier to have it in discs that in a cylinder