Question

you have two containers. one is a cylinder with a height of 15 inches and a diameter of 10 inches. the other side is a cube with sides of 12 inches.
what is the volume of the cylinder? what is the volume of the cube?

Answer 1

volume of a cylendar = pi r^2 h. cube is length times width times depth

Answer 2

so the volume of the cylinder would be 1177.5 inches^3

Answer 3

i get 1178.09, lemme try it again though

Answer 4

well for pie i just use the first 3 numbers.. 3.14

Answer 5

ahh, yup that will do it

Answer 6

and the cube would be 12*12=144

Answer 7

that would only be the surface area of one side of the cube, its 12^3 height, width, and depth

Answer 8

so 1728inches^3

Answer 9

you got it

Answer 10

one more question: how many gallons of water are needed to fill the cylinder? (hint: 1 gallon of water is .1337ft^3)

Answer 11

if you know one gallon takes up .1337 ft cubed, and the cyl has 1177 ft cubed of space then some division will get you how many gallons per cyl

Answer 12

and are you sure its .1337 per gallon? that seems kinda small considering a gallon of milk is roughly a cubic foot in real life

Answer 13

that means you'd need 10 gallons to fill one cubic foot, just seems big to me but maybe im wrong?

Answer 14

oooooh we are dealing in inches here. your .1137 ft needs to be converted to inches (easy, 12 inches per foot) to get you cubic inches or you can go the other way anf find out how many cubic feet the cyl has and then do your division. gotta make sure the scales are correct and then its simple division

Answer 15

i cant convert worth crap i dont understand converting

Answer 16

okay, if you have 12 inches per foot, theres 24 inches in 2 feet (12*2), theres 36 inches in 3 feet (12*3). so that also means you could take some random number of inches, lets pick 247 (totally random) and we know that 20.5833 feet is the same as 247 inches. (247/12). do you see how it works?

Answer 17

multiplying and dividing are really just the same thing, one is forward and one is backwards. division tells you how many of A is in B. multiplying tells you if you had A number of groups and B number of items per group, what is the total number of items

Answer 18

ok

Answer 19

so i would do 1177.5*12

Answer 20

almost, conversion of cubic numbers is a bit more trickey. you can either convert before finding the answer in ^3 or if you do it afterward you need to remember that your dealing with a volume in 3 dimensions. because think about the physical shape of a cubic foot (a box that is a ft by ft by ft) now think about 12 1 inch cubes (little bigger than 12 dice) not quite the same size as eachother. thats because your forgetting a whole dimensions

Answer 21

however, if you know taht there are 1728 cubic inches per cubic foot (thats a true statement btw) then you can do your one to one conversions

Answer 22

ok

Answer 23

does that make sense?

Answer 24

kinda

Answer 25

well to get that 1728 number all you are doing is saying, i have 12 units up, 12 units deep and 12 units wide.

Answer 26

ok

Answer 27

so if you wanted to convert 4 cubic feet it would just be how many inches in one cubic foot times 4, aka 1728 times 4

Answer 28

1177.5*4=4710

Answer 29

sorry no, its not times 4 because that would be a 2X2X2 ft square. to find for a 4ft cubed would be 4*12=48 48^3=110592

Answer 30

i meant to say 64 not 4 because it expands exponentially ie: 4^3 is what you multiply by (4^3=64)

Answer 31

haha now i went and confused you more by typo-ing. im sorry about that. you have to remember that the number your multiplying by is cubed as well.

Answer 32

im already confused

Answer 33

its that 1728 number (how many cubic inches in a cubic foot) times how many cubic feet your finding ^3 example: 3 cubic feet has 1728*3^3 cubic inches in it. 24 cubic feet has 1728*24^3 cubic inches in it

Answer 34

what i was saying before is you can figure it out by converting first if you want. so your 3 cubic feet has 3 feet in each direction. thats the same as 3*12=36 inches in each direction. now you can find cubic inces using those dimensions instead

Answer 35

so 1177.5*3^3

Answer 36

wait a second. your cyl you have in inch form and your gallons is in feet form. are you going to do your comparison in feet or inches because we need them both in the same format first

Answer 37

ft

Answer 38

so we need to divide 1177.5 in cubed by 12 inches cubed, that gets us feet

Answer 39

oh! heres an idea that one of my teaches tried with us years ago, maybe that will help you with conversions, you can use it for any conversion you want

Answer 40

ok

Answer 41

well apparently i have no idea how to use the equations thinger on this site, so thats not going to work. basically you just need to know how many units to convert and then write out equivalent fractions and then cross out matching units that cancel out.

Answer 42

huh?

Answer 43

http://www.purplemath.com/modules/units.htm

Answer 44

i give up onthis one