Question

An hourglass, composed of two identical cones, is 12 cm tall. The radius of each cone is 3 cm. If
you want to fill the bottom half of the hourglass
full of salt, how much salt will you need?
Explain the method you would use to find the amount of salt.

Answer 1

THT DOESNT HELP

Answer 2

@lexikaylynn

Answer 3

@phi plz help me

Answer 4

First, do you know the shape of the hour glass?
it sounds like it would be two cones, on on top of the other , right ?

Answer 5

right

Answer 6

and what is
bottom half of the hourglass

any idea what shape that is ?

Answer 7

a cone?

Answer 8

yes, just one of the cones (if 2 cones is the whole hourglass, it makes sense 1/2 of the hourglass is 1 cone)

Answer 9

yep right

Answer 10

you want to fill the bottom half of the hourglass

which means
you want to fill one of the cones.

fill with stuff (salt in this case) reminds me of volume (as opposed to surface area, or something else)

Look in your notes for volume of a cone.

Answer 11

i cant i have like 5 mins to submit my answer....plz help me!

Answer 12

@phi

Answer 13

Ive tried i just cant fogure this prob out!

Answer 14

this is not figuring out. this is writing down the formula for volume of a cone
You must either memorize it, or know how to find it.

Answer 15

i cant find it....2mins 33 secs

Answer 16

left

Answer 17

AHHHHHHHHHHHHHH

Answer 18

PLZ!!

Answer 19

@pooja195

Answer 20

1 min 45 secs

Answer 21

see http://www.wikihow.com/Sample/Volume-of-a-Cone-Diagram

Answer 22

thnx!!!!!!!!!!