Question

find the volume

Answer 1

base x^2+y^2=9; semicircle

Answer 2

semicircle doesn't have a volume. you mean sphere, right??

Answer 3

semicircle slices**

Answer 4

Or area?

Answer 5

that's how its said on my wksht

Answer 6

its volume

Answer 7

Well, it is zero because x^2+y^2=9 is plane.

Answer 8

i thought itd be pi r ^2 over 2? cuz its half a circle

Answer 9

It's zero because finding volume of plane is like finding area of a line.

Answer 10

Sharon, you want to find the volume of a semisphere with a semicircle cross-section represented on the cartesian plane with the equation x^2 + y^2 = 9?

Answer 11

@sharonribs

Answer 12

i guess so.....

Answer 13

Ok that's easy.

Answer 14

thats all it says tho x^2+y^2= 9 ; semi circle slices
find the volume

Answer 15

I think he is saying that the base of the solid is a circle and there are semi circle cross sections above it.

Answer 16

so it would be half of a sphere with a radius of 3

Answer 17

or (4 Pi r^2)/6

Answer 18

but ure supposed to integrate

Answer 19

well you can do the same thing by making it a function of x. In this case y = √(x - 9) and then you get a semi circle base. do the integration like you normally would and then multiply by 2 at the end, since you now have half of the base.

Answer 20

Before we proceed, the volume that we are looking for is of a 3-d figure. The thing is, that more than one solid can have a semicircular cross section/base on the 2-d plane. Is the semicircle the base of a half Cylinder/Or is it the base of part of a sphere? We need this info to solve the problem.

@sharonribs

Answer 21

Or why don't you take a picture of the problem and upload it? @sharonribs

Answer 22

the crossections in that case will also be quarter circles instead of semi circles so you will have to integrate accordingly

Answer 23

You know I am pretty confident that this is a hemisphere that you're supposed to integrate to find the volume of. @sharonribs

Answer 24

thereis no picture on the wksht

Answer 25

Can you type up the WHOLE question with any details it gives and post it?

@sharonribs

Answer 26

find the volume. check your work using what you know from geometry. does it matter which axis is perpendicular to your slices?

Answer 27

thats it

Answer 28

Ok got it. Is there any pictures or anything like that? Also, what topic is this problem from?
Finite Sums/Rieman Sums/Integration?

Answer 29

volume of a solid by plane slicing

Answer 30

8-5

Answer 31

http://www.cliffsnotes.com/study_guide/Volumes-of-Solids-with-Known-Cross-Sections.topicArticleId-39909,articleId-39906.html @genius12 this is the type of problem he is dealing with.