Math people? For the Imperially challenged

Hope1964 · 05-28-2012, 10:24 AM

We have a 1400 sq ft area that we want to cover with one inch of sand. How many cubic yards do we need??

lamaga · 05-28-2012, 10:24 AM

Alas, DH is in the shower -- he can do this kind of thing in his head!

Hope1964 · 05-28-2012, 10:30 AM

Yes, yes it would.

Hope1964 · 05-28-2012, 10:32 AM

If I have done this right, it should be 4.33. Can anyone confirm this for me?

joe kidd · 05-28-2012, 10:37 AM

Unless the math has something to do with my commission at work I have no interest. LOL
There are 144 sq inches in a sq ft. So 1400 sq ft is 201,600 sq inches.
There are 1,728 cubic inches in one cubic foot. So 201,600 divided by 1,728 equals 116.67 cubic feet. There are 27 cubic feet in a cubic yard, to 116.67 divided by 27 comes to 4.32 cubic yards.
............I think.

Hope1964 · 05-28-2012, 10:46 AM

Well, we're pretty close to each other so I am going to say we're right

Hope1964 · 05-28-2012, 10:47 AM

Here's another one: How many cubic yards will a trailer that is 37 sq ft and 15" deep hold?

Dollystanford · 05-28-2012, 10:59 AM

sorry my brain is filled with pink fluff and pecs

Lon · 05-28-2012, 11:02 AM

google is our friend:

https://www.google.ca/search?q=20160...w=1421&bih=696

Lon · 05-28-2012, 11:05 AM

Quote:

Originally Posted by Hope1964

Here's another one: How many cubic yards will a trailer that is 37 sq ft and 15" deep hold?

1.7 cubic yards

https://www.google.ca/search?q=20160...w=1421&bih=696

joe kidd · 05-28-2012, 11:07 AM

Hey Hope. You are in Canada, wouldn't you need cubic meters? LOL!

Hope1964 · 05-28-2012, 11:15 AM

Quote:

Originally Posted by joe kidd

Hey Hope. You are in Canada, wouldn't you need cubic meters? LOL!

You'd think so wouldn't you?? It's America's fault - when they buy from American suppliers I think they just leave it that way. There's the odd thing up here that happens with.

Hope1964 · 05-28-2012, 11:15 AM

Lon, THANK you!!!!!

shy_guy · 05-28-2012, 11:26 AM

Quote:

Originally Posted by joe kidd

Unless the math has something to do with my commission at work I have no interest. LOL
There are 144 sq inches in a sq ft. So 1400 sq ft is 201,600 sq inches.
There are 1,728 cubic inches in one cubic foot. So 201,600 divided by 1,728 equals 116.67 cubic feet. There are 27 cubic feet in a cubic yard, to 116.67 divided by 27 comes to 4.32 cubic yards.
............I think.

Correct. There is an easier way to do it, I think. I don't think I have superscript or subscript notation avaiable in the editor here, so let me just use the worded or ^ notation for exponents.

The number of cubic inches in a cubic yard is 36 cubed or 36^3. You could convert to feet, but since your smallest dimension (depth) is in inches, I'd use inches like you did. It would be (201,600)/(36^3) which is the 4.32 you arrived at.

You probably can't buy 4.32 cubic yards, so when estimating how much to go over, consider a couple of real-world things: 1) you probably can't get even coversage of exactly 1 inch and 2) if you have any kind of hill, or are trying to smooth out irregularities in the yard, you either change depth or change the amount of surface in the yard itself.

So just buy a little extra for things like that.

shy_guy · 05-28-2012, 11:31 AM

Quote:

Originally Posted by Hope1964

Here's another one: How many cubic yards will a trailer that is 37 sq ft and 15" deep hold?

If you don't heap it up?

37 X 144 X 15 = 79,902 cubic inches

79,902/(36^3) =~ 1.71 cubic yards.

But as with most real world implementations, that may not reflect what you actually do because it's unlikely you're going to fill exactly to the edge and be smooth all the way across. You'll probably be a little lower than the top on the edges and heap in the middle.

But it's a good starting point.