This is a place for the community of learners in Room 8-17 to learn and enjoy math. It is an extension of the classroom making it accessible 24 hours a day, 7 days a week.
Thursday, February 17, 2011
Tianna's Textbook Homework
Demvry's Textbook Homework
Questions 18 and 19
Question:
18.Suki has 30 small linking cubes.
a)She wants to use 18 of them to make a large cube. Is this possible? Why or why not?
b)What number of linking cubes would she use to construct the largest cube she can possibly make?
Answer:
a)I say this is not possible because I think there is no whole number that could be cubed to be able to equal 18.
b)She would probably need to use 27 cubes to make the largest cube possible (3x3x3).
Question:
19.Melissa has three glass vases. She wants to use one as a decorative fish tank for Harvey the guppy. Which will give Harvey the most water to swim in.
Answer:
The volume of the one shaped as a cube is 343cm2.
The volume of the one shaped as a rectangular prism is 360cm2.
The volume of the one shaped as a triangular prism is 367.5cm3.
According to the volumes, the triangular prism would've the most water for Harvey the guppy to swim in.
Here are some videos!
Volume of a cube!
Volume of a rectangular prism!
Volume of a triangular prism!
Here is a link to help you understand it better!
http://www.math.com/tables/geometry/volumes.htm
Inform me if I made a mistake or tell me what I could improve on. Thanks.
Ps - If the letters are over or undersized, ignore it and I'll try to find a way to fix it. If I can't, I'm sorry.
Justin Lorenzo's Math Textbook Homework
Pages 259-260 Answers to # 7, 12, 14 (Math Textbook)
7.)
A) V= B x H ÷ 2 x H
V= 12 x 7 ÷ 2 x H
V= 42cm2 x 7cm2
V= 294cm3
B) V= B x H ÷ 2 x H
V= 8.1 x 2.2 ÷ 2 x 15
V= 8.91m2 x 15m2
V= 133.65m3
C) V= B x H ÷ 2 x H
V= 320 x 210 ÷ 2 x 400 / 67 200 ÷ 2 x 4
V= 33 600mm2 x 4mm2
V= 13 440 000 mm3
12.)
Base (cm)
7
18
20
Height Of Triangle (cm)
10
10
5
Height of prism (cm)
70
1080
700
14.)
V= B x H ÷ 2 x H
V= 15 x 8 ÷ 2 x 80
V= 60cm2 x 80cm2
V= 4800 cm3
If there are any other solutions, or mistakes I have typed please feel free to comment!
HWB pg. 80 & 81 #4, 6, 8
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 is are links to help you out with finding out prism: 1, 2, and 3.
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
Wednesday, February 16, 2011
Diana's Homework Book Post.
C)
Both rectangular prisms have the volume of 200cm.
The need to put 24.3m3 of water in the pool.
Jumbo:
r= d÷2 V=(pi.r.r)x h
r= 20÷2 V=(3.14x10x10)x40
r=10cm V=314 x 40
V=12'560cm³
Popcorn Lover's:
r= d÷2 V=(pi.r.r)x h
r= 30÷2 V=(3.14x15x15)x20
r= 15cm V= 7065 x 20
V= 14'130cm³
Martha should buy the popcorn lover's one because it has a greater volume than the Jumbo one.Popcorn Lover's volume is 14,130cm³ and Jumbo's 12,560cm³.
Chapter 7.4
Outside;
r=d÷2 V=(pi.r.r)x h
r= 1÷2 V=(3.14x0.5x0.5)x10
r=0.5m V= 0.785 x 10
V= 7.85m³
Inside;
r= d÷2 V=(pi.r.r)x h
r= 0.8÷ 2 V=(3.14x0.4x0.4)x10
r= 0.4m V=0.5024 x 10
V= 5.024m³
You Subtract the volume of the inside from the volume of the outside.
7.85m³ - 5.024m³ = 2.826m³
The volume of concrete needed to make the culvert is 2.826m³
Mike's Volume Post
Show You Know
A) Area of Base X Height
L x W x H
8.5cm x 4cm x 5cm
170cm3
B) L x W x H
3cm x 3cm x 3cm 3 x 3 = 9cm2
9cm2 x 3cm = 27cm3
C)
B x H
----- = H
2
9 x 5
----- = 22.cm2
2
22.5cm2 x 8cm = 180cm3
OR
5 x 9 x 8/2 = 180cm3
A website you can visit about volume.
Casey's volume post 3, 9, 11
15 cm2 x 4 cm = 60 cm3
b) area of the basexheight
18 cm2 x 12 cm = 216 cm3
c) area of basexheight
96 cm2 x 20 cm = 1920 cm3
9. There are four ways to build a rectangular prism from 16 cm cubes.
11. area of the basexheight
10.4 cm2 x 9 cm = 93.6 cm3
p.s. sorry for no videos they would not work on my computer
a) v= (pi x r x r) x h b) v= (pi x r x r) x h
v= ( 3.14 x 5 x 5) x 23 v= (3.14 x 14 x 14) x 12
v= 78.5 cm2 x 23 cm v= 615.44 cm2 x 12 cm
v= 1805.5 cm3 v= 7385.28 cm3
c) v= (pi x r x r) x h
v= (3.14 x 0.5 x 0.5) x 1.5
v= 0.785 cm2 x 1.5 cm
v= 1.1775 cm3
Answer: 45 cm long, because they both have the same volume.
Robin's Volume Scribe Post
This Question i was confused on sorry i didn't answer it .
5)Determine the volume of each right rectangular prism.
L.W.H
3x4=12cm2
12x5=60cm3
L.W.H
3x5=15cm2
15x4=60cm3
B)
L.W.H 6x8=120cm2
120x8=960cm3
L.W.H
8x6=48cm2
48x20=960cm3
8) Nina uses 15 centimeter cubes to make the base of the rectangular prism. Determine the volume if the prism has a total of 5 layers of cubes. Show your thinking
Answer) So you have 5 layer with 15cm2 then you times your centimeter like (15x5)
to get 75cm3.
10) A water through is in a shape of a right triangular prism with base area of 1250 cm2 and a height of 100 cm. How much water can be put in there before it overflows?
Answer) 1250cm2x100cm=125 000cm3
it will be 125 00cm3 before it get overflows.
Here a video to understand more about volume:
Here a link about volume: http://library.thinkquest.org/20991/geo/solids.html
Tell me if i did anything wrong.
Monday, February 14, 2011
Tonie's Volume Scribe Post
- any face of a prism that shows the named shape of the prism
- the base of a rectagular prism is any face
- the base of a triangular prism is a triangular face
- the base of a cylinder is a circular face
- the perpendicular distance between the two bases of a prisms of cylinder
- the ammount of space an object occupies
- measured in cubic units
- the different position of an object formed by translating, rotating, or reflecting the object
l x w x h
d/2=r
4cm=r
3.14.r.r.h
3.14.4.4=50.24cm2
50.24cm2 x 10 =502.4cm3
Here are some videos to help you guys out (:
Here are some links to help you out more!! (:
link1
link2
link3
Answer:
Jumbo Container:
d/2=r
20/2=r
10=r
V=pi.r.r.h
V=(3.14 .10 .10) .40
V= 314.40
V=12,560 cm^3
Popcorn Lover's Container
d/2=r
30/2=r
15=r
V=pi.r.r.h
V=(3.14.15.15).40
V= 706.2 . 40
V=28,248cm^3
Martha should buy the 'Popcorn Lover's' container because the volume is bigger.
Answers:
Wednesday, February 2, 2011
Cylinder Homework
Tuesday, February 1, 2011
Marie's Volume Post
- The bases are circles
- Radius is half a diameter
- Diameter cuts a circle in half
- Circumference is the perimeter of a circle
- Pi is the ratio between circumference/diameter or 3.14
Formulas:
Circumference - pi (d) = c
Radius - d/2 = r
Diameter - 2r = d or c/pi
Area of a circle:
pi (r²) or pi (r) (r)
Net of a cylinder:
Formula:
lxw = a
pi (r) (r) = a
d = 2r
r = d/2
c = pi(d)
Here are the answers on our homework.
*I'm only showing one of each (diameter, circumference, radius) because Mr. Harbeck told me to.*
Here is a link on cylinders.
A video to help you learn the surface area of a cylinder:
Cylinder Volume and Volume Problems
7.3