## Monday, February 14, 2011

### Glenesse's Homework Book Post

Homework Book
Pages 78-79
Even #'s 4, 6, 8

Questions:
4. Calculate the volume of each prism or cylinder.
a)
b)
c)

4)-a) Area of base X height
100 cm² X 4 cm = 400 cm³

b) Area of base X height
113 cm² X 3 cm = 339 cm³

c) Area of base X height
80 cm² X 12 cm = 960 cm³

Question:
6) Which rectangular prism has the larger volume? Show your thinking.
a)
b)

6)-a)
1-Area of base X height
40 cm² X 5 cm = 200 cm³
2-Area of base X height
20 cm² X 10 cm = 200 cm³

They both have a volume of 200 cm³.

b)
1-Area of base X height
10.5 m² X 1 m = 10.5 m³
2-Area of base X height
3 m² X 3.5 m = 10.5 m³

They both have a volume of 10.5 m³.

Question:
Nikki and Taylor have to fill the pool this summer. The area of the pool bottom is 27 m². The height that the water needs to be is 0.9 m. How much water do they need to put in the pool?

Area of base X height
27 m² X 0.9 m = 24.3 m³

Here is a video on how to find the volume of a prism.

Cylinder Volume and Volume Problems

Jumbo
r=d/2
r=20/2
r=10cm

v=π x r x r x h
v=(3.14 x 10 x 10) x 40
v=314cm^2 x 40cm
v=12560cm^3

Popcorn Lovers
r=d/2
r=30/2
r=15cm

v=π x r x r x h
v=(3.14 x 15 x 15) x 20
v=706.5cm^2 x 20cm
v=14130cm^3

Martha should buy the Popcorn Lovers container

a)
r=d/2
r=120/2
r=60cm

v=π x r x r x h
v=(3.14 x 60 x 60) x 18
v=11304cm^2 x 18cm
v=203472cm^3

b)
v=l x w x h
v=30 x 22 x 20
v=660cm^2 x 20
v=13200cm^3

c) 203472cm^3/13200cm^3 = 15.4 pails