## Thursday, February 17, 2011

### HWB pg. 80 & 81 #4, 6, 8

4. Calculate the volume of each rectangular prism.
a) l = 15cm, w = 12cm, h = 3cm

v = l x w x h
15cm x 12cm = 180cm2
180cm2 x 3 = 540cm3

b)

v = l x w x h
8.5m x 7m = 59.5m2
59.5m2 x 2m = 119m3

c)

v = l x w x h
20cm x 8cm = 160cm2
160cm2 x 16cm = 2560cm3

6. Calculate the volume of each right triangular prism. Express the answer to the nearest tenth.

a)

v = b x h1/2 x h2
7.2 x 4.5cm/2 = 16.2cm2
16.2cm2 x 10cm = 162cm3

b)
v = b x h1/2 x h2
5 x 3/2 = 7.5cm2
7.5 x 8.5 = 63.8m3

c) A prism where the case of the triangle is 4m, the height of the triangle is 5m, and the prism height is 12m.

v = b x h1/2 x h2
4 x 5/2 = 10m2
10m2 x 12 = 120m3

8. Wab needs to buy drinks for the summer barbeque. Both containers are the same price. Which one holds more?

apple juice:
v = l x w x h
6cm x 9cm = 54cm2
54cm2 x 4.5cm = 243cm3

orange juice:
v = l x w x h
6cm x 10cm = 60cm2
60cm2 x 3.75 = 225cm3

Apple juice holds more juice (y)

Here's a video:

URL of pictures:
http://www.clker.com/clipart-3934.html
http://www.ifood.tv/blog/apple-juice-health-benefits

Please tell me if I did any mistakes or what I can do better next time. (:

Cylinder Volume and Volume Problems

Chapter 7.3:

v = π r r h
v = (3.14x5cmx5xm) x 23
v = 1805.5cm3

Chapter 7.4:

Volume of cylinder: Volume of triangular prism:

r=d/2 bxh1/2 x h2
r=25/2 40x35/2 x 140cm2
r=12.5cm2 = 98000cm3

v=π r r h
v= (3.14x12.5x12.5)x100
v=49062.5cm3

98000cm3 - 49062.5cm3 = 48937.5cm3

Video:

* I meant to say cubed when I said squared on the part where i was supposed to say cubed :P