Question

what length of soled cylinder 2 cm in diamatre must be taken to recast into a ahollow cylinder of external diametre 20cm,0.25cm thick and 15cm long?

Answer 1

@kittiwitti1

Answer 2

Oh. Uh....
Can't help you with that. e_e
@hartnn

Answer 3

why cany u help me with this??

Answer 4

cant*

Answer 5

I suck at geometry.

Answer 6

ok?

Answer 7

I'm gonna afk for 20 minutes while I try to solve this. e_e;

Answer 8

...

Answer 9

I told you I suck at geometry....

Answer 10

thanks anyways

Answer 11

np e_e

Answer 12

When you say "0.25 cm thick" do you mean width?

Answer 13

idk

Answer 14

....how am I supposed to give you the correct answer then

Answer 15

i haven't understood the sum

Answer 16

Sum?

Answer 17

does this sound accurate?

Answer 18

so the solid cylinder is melted down and recast into a hollow cylinder

Answer 19

and you want know how much solid cylinder (in length) do you need to melt down and recast into the hollow cylinder.

Answer 20

I think I got the answer...
this is when I wish I had a draw tablet e_e;

Answer 21

helps to draw the hollow cylinder

Answer 22

I did on my paper. xD

Answer 23

?

Answer 24

You know what, listen to @perl... she's the expert xD
(You are a she right e_e?)

Answer 25

I am using formula
Volume = Pi * r^2 * h

Answer 26

now?

Answer 27

@perl

Answer 28

100-64?

Answer 29

24*15?

Answer 30

thats no answer

Answer 31

in my book its 74.06

Answer 32

there was a typo

Answer 33

?

Answer 34

Volume of solid cylinder

formula : V = Pi * radius^2 * height
substitute:
V1 = pi * (1)^2 * h


Volume of hollow cylinder:
formula : V = Pi * (outer_radius^2 - inner_radius^2 ) * height
substitute
V2 = pi * [ 10^2 - (10 - .25)^2 ] * 15


From the problem we must have V1 = V2

Pi * (1)^2 * h = pi * (10^2 - (10 - .25)^2 )*15

divide both sides by Pi

1* h = [ 10^2 - (10 - .25)^2 ] * 15
h = ( 10^2 - (10 - .25)^2) * 15
h = ( 10^2 - 9.75^2 ) * 15
h = ( 100 - `95.0625`) * 15
h = `4.9375` * 15
h = 74.0625