volumes question (1 Viewer)

[bleakarcher]

how the fuk do u do q5) b)

http://4unitmaths.com/2003WRpaper.pdf

 

[thoth1]

you find the volume of the whole sphere and call that V1. then you find volume of cylinder and call it V2.
therefore Vtot of remaining sphere = V1-V2

posting solution in a sec

 

[K4M1N3]

you find the volume of the whole sphere and call that V1. then you find volume of cylinder and call it V2.
therefore Vtot of remaining sphere = V1-V2

posting solution in a sec

But your not accounting for the part of the cylinder that extrudes the sphere...

 

[thoth1]

crap my way doesnt work.

 

[bleakarcher]

i tryed rotating the semi-circle y=sqrt[2-x^2] about the line y=-1.

 

[bleakarcher]

lol. i did this yesterday at night as i was half a sleep. i figured lol. u must rotate the semi-circle y=sqrt[4-x^2] about the line y=-1.

 

[bleakarcher]

there should be a pi there in the exact volume, so i do not think so. but u just rotate the region bounded by the curve y=sqrt[4-x^2] and the x-axis about the line y=-1 to obtain the volume.

 

[thoth1]

 

[Drongoski]

Good work thoth1


I just worked out the same answer: cubic units.

In uni this would be done more directly via a double integral.