Tuesday, June 03, 2008

More Review

Surface Area and Volume

Probability

1 comment:

Romulo8-16 said...

Surface Area and Volume

What we know about the Rectangular Hay Bale

Length : 90cm
Width : 45cm
Height : 35cm

What we know about the Round Hay
Bale

Diameter: 100
Height : 120

So first thing you need to do is find the volume of the rectangular hay bale.

To get the volume of the rectangular hay bale you use the same formula you use to get the volume of a rectangular prism. The formula is

Base X Height or
Length X Width X Height

So now you write the formula you're going to use. I'll be using the LxWxH formula.

V= LxWxH
V= 45x90
V= 4050x35
V= 141 750cm³

The volume of the rectangular hay bale= 141 750cm³

Now you find the volume of the round hay bale. The formula you use to find the volume in a cylinder is

Base X Height or
Area one of the circles X Height or
(pi)r² X Height

So now to set it up.

V= Base X Height
V= ? X 120

We don't know what the base is yet so we have to find it out.

To get the base it's the area of one of the circles of the cylinder.

The formula to get that is (pi)r²

Since we also don't know the radius yet we still have to find that out too.

To get the radius when we only have the diameter we use the formula d/2.

R= 100/2
R= 50

Now we know what the radius is 50.
We now use the formula (pi)r² to get the area of one of the circles.

Area= (pi)r²
A= (3.14)50²
A= (3.14)2500
A= 3.14x2500
A= 7850

Since we know the area/base we can find the volume of the round hay bale.

V= Base X Height
V= 7850x120
V= 942 000cm³

The volume of the round hay
bale= 942 000cm³

Now we need to know how many rectangular bales of hay it takes to equal one round hay bale.

To get the answer we need to divide 942 000 by 141 750.

942 000/141 750= 6.645

Now we have to round to the nearest whole number which is 7.

So the answer to the question is

It takes 7 rectangular bales of hay to equal one round hay bale