Breanna's Volume Post

Volume Post

This is a Cylinder problem.

Pi.r.r.h
πx5x5=79cm^3
79x23=V
1,817=V

This is my triangular prism problem.

a) Yes, he has enough, he only needs 16 triangles
b) 5.6x6.8/2x1.18= 22.46^2

Surface Area and Volume

Here is a question from 7.3 in the text book :










r=d/2 v=πr² x h
r=8/2 v=(3.14x4x4) x 10m
r=4m v=50.24m² x 10m
v= 502.4m³
Now, since it is only half of a cylinder, I have to divide by 2
502.4m³/ 2= 251.2m³

The area of the semi-circular trough is 251.2cm³

Here is a question from 7.4 in the textbook :


____
³ )8000 = 20 d/2=r v= πr² x h
20/2=r v= (3.14x10x10) x 20
10cm=r v= 314cm²x 20cm
v= 6280cm³
The volume of the vase is 6280cm³

Surface Area and Volume Post

Show You Know pg. 185

Calculate the surface area of this cylinder to the nearest tenth of a square centimetre.

Show You Know pg.185

Calculate the surface area of a cylindrical waste bucket without a lid that measures 28 cm high and 18 cm in diameter. Give your answer to the nearest square centimetre.


1. What are the similarities and differences between finding the surface area of a prism and finding the surface area of a cylinder?


3. a) Draw a net for this cylinder. b) Sketch a different net for this cylinder


5. Find the surface area of each object to the nearest tenth of a square unit.


Cylinder Problems and Volume Problems



d/2=r

8/2=r

4m=r

v= π.r.r.h

v=(3.14 x 4 x 4 ) x 10

v=50.25cm^2 x 10m

v=502.4 cm^3

502.4/2 = 251.2m^3

Emily's Circle Surface Area Scribe Post

Notes:

-bases are circles
-diameter cuts a circle in half
-radius is half the diameter
-circumference is the perimeter of a circle
-pi is the ratio between circumference/diameter or 3.14
-circumference, pi.d=c
-radius, d/2=r
-diameter, r.2=d or c/pi=d
-area of a square, pi.r squared or pi.r.r
-make a square with the radius and multiply by pi

EX.





Here are some questions we did in class:





Here is a LINK I found on area.



Here is a video:

What is the radius of a circle with a diameter of 8cm?

5cm
4cm2
16cm
4cm

or View Results

Create your own poll at Flisti.com


Cylinder Volume and Volume Problems

Volume Problem

d/2=r
8/2=r
4m=r

pi.r.r.h
(3.14x4x4)x10
(50.24m^2)10m
502.4m^3

Since it is a semi circular trough the area has to be divided by two.
502.4cm^3/2=251.2m^3

The volume of the semi circle is 251.2m^3


Volume Problem

To convert a meter to a centimeter you multiply it by 100.

0.25mx100=25cm

d=25cm

d/2=r

25/2=r

12.5cm=r

1mx100=100cm

height of cylinder= 100cm

0.35mx100=35cm

height of triangle=35cm

0.4mx100=40cm

base of triangle=40cm

1.4mx100=140cm

height of the triangular prism=140cm

pi.r.r.h

(3.14x12.5cmx12.5cm)x100cm

(490.625cm^2)x100cm

v=49062.5cm^3

bxh/2.h

(40cmx35cm/2)x140cm

(700cm^2)x140cm

v=98000cm^3

98000cm^3-49062.5cm^3=48937.5cm^3

48937.5cm^3 is needed to make the clay planter.

Here is the volume video I created:

Text Book Questions

Question 9:

Kaitlyn and Hakim each bought a tube of candy. Both containers cost the same amount. Which container required more plastic to make?

Candy tube A:

d/2 = r

7/2 = r

3.5 cm = r

TSA= (2 x Pi x r x r)+(2 x r x Pi x h)

TSA= (2 x 3.14 x 3.5 x 3.5)+(2 x 3.5 x 3.14 x 122)

TSA= (76.93cm2)+(2681.56cm2)

TSA= 2758cm2

The amount of plastic needed to make tube A is 2758cm2.

Candy tube B:

d/2 = r

11/2 = r

5.5 cm = r

TSA= (2 x Pi x r x r)+(2 x r x Pi x h)

TSA= (2 x 3.14 x 5.5 x 5.5)+(2 x 5.5 x 3.14 x 85)

TSA= (189.97cm2)+(2935.9cm2)

TSA= 3125.87cm2

The amount of plastic needed to make tube B is 3125.87cm2.

The tube of candy that needs more plastic is B.

Question 10:

Paper towel is rolled around a cardboard tube. Calcula

te the outside surface area of the tube.

d =2r

d =2 x 2

d =4cm

c = Pi x d

c = 3.14 x 4

c = 12.56cm

l x w = area of a square

12.56 x 27.5 = area of a square

345.4cm2 = area of a square

The out side surface area of the tube is 345.4cm2.

Cylinder Volume and Volume ProblemsQuestion 1:

Answer:

Jumbo Popcorn

d/2=r

20/2=r

10cm=r

v=(pir^2)h

v=(3.14x10x10)40

v=314cm^2x40cm

v=12650cm^3

Popcorn lover's

d/2=r

30/2=r

15cm=r

v=(pir^2)h

v=(3.14x15x15)20

v=706.5cm^2x20cm

v=14130cm^3

Here is my math video

If Martha wants to get more popcorn for her money she should by the popcorn lover's container.

Question 2:

d/2=r

10/2=r

5cm=r

v=(pir^2)h

v=(3.14x5x5)40

v=78.5cm^2x40cm

v=3140cm^3

d/2=r

8/2=r

4cm=r

v=(pir^2)h

v=(3.14x4x4)40

v=50.24cm^2x40cm

v=2009.6cm^3

3140cm^3 - 2009.6cm^3=1130.4cm^3

Meldrick's Circle Surface Area Post

Here are the notes that we took down in class:

-the bases of a cylinder are circles

-the radius is half a diameter

-the diameter cuts a circle in half

-the circumference is the perimeter of a circle

-pi - the ratio between the circumference and diameter- 3.14159.. and on.. and on- you get it, right?

Here are the formulas that we also took down in class:

Radius

d/2=r

Diameter

2r=d or c/pi=d

Circumference

pi(d)=c *remember, brackets mean multiplying*

Area (of a circle)

Pi(r squared)

For example:

Here are the homework circles:

This is a link that is dedicated to circles.

Here is a link to a video that I couldn't embed.

7.3


a) When the radius of a cylinder is doubled, the volume of a cylinder is multiplied by 4.
EX.
v = π*r^2*h
v = 3.14*1²*1
v = 3.14*1*1
v = 3.14 cm³

v = π*r^2*h
v = 3.14*2²*1
v = 3.14*4*1
v = 12.56 cm³

b)When the height of a cylinder is doubled, the volume of the cylinder is doubled.
EX.
v = π*r^2*h
v = 3.14*1²*1
v = 3.14*1*1
v = 3.14 cm³

v = π*r^2*h
v = 3.14*1²*2
v = 3.14*1*2
v = 6.28 cm³

7.4

The volume of the triangular prism shown is 48 cm^3. What is the value of the missing measurement?
The value of the missing measurement is 5.
EX.

[v/h²]*2 = area of the base

[48 cm³/8 cm]*2 = area of the base

6 cm²*2 = area of the base

12 cm² = area of the base

area of the base/h¹ = base

12 cm²/4 cm = base

3 cm = base

Now, if...

h¹ = a

base = b

■ = c

a²+b² = c²

4²+3² = c²

16+9 = c²

25 cm² = c²

sqrt of c² = c

sqrt of 25 = c

5 = c

5 = ■

Surface Area Quiz Answers

Here is a link.

Cylinder Volume and Volume Problems
Example from 7.3:

Example from 7.4:

Anna's Surface Area

Finding the surface area of Rectangular Prism and Triangular Prism.

Triangular Prism



































Rectangular Prism.



















Cylinder Volume and Volume Problems

7.3 question

v= π . r^2 . h
v= (3.14 x 5 x 5)x23cm
v=78.5 x 23cm
v= 1805.5 cm^3












7.4 question




a) Yes, he has enough small triangular Prisms to make a giant prism with a base of 5.6m and height of 6.8m.

b) v=b.h^1/2.h^2

v=(5.6x1.18)x6.8 m

v= 10.08 x 6.8 m

v= 69 m^3

The Volume of the new prism is 69m^3

Homework Book Pg 54-55

Choose 3 questions from pages 54 and 55

2. Calculate the surface area of each rectangular

prism to the nearest tenth of a centimeter squared.

length x width = a

S- 5 x 3.2 = 16 cm2

- 5 x 3.2 = 16 cm2

F- 11.5 x 5 = 57.5 cm2

- 11.5 x 5 = 57.5 cm2

T- 11.5 x 3.2 = 36.8 cm2

- 11.5 x 3.2 = 36.8 cm2

________________________________

Total Surface Area =220.6 cm2

length x width = a

F- 12 x 10.4 = 124.8 cm2

- 12 x 10.4 = 124.8 cm2

T- 10.4 x 4.5 = 46.8 cm2

- 10.4 x 4.5 = 46.8 cm2

S- 12 x 4.5 = 54 cm2

- 12 x 4.5 = 54 cm2

________________________

Total Surface Area = 451.2 cm2

3. Find the surface area of each triangular

prism to the nearest tenth of a meter squared.

a of a triangle = base x height divided by 2

a of rectangle = length x width

8 x 2.5 = 20 m2

10.6 x 2.5 = 26.5 m2

2.5 x 7m = 17.5 m2

7 x 8 = 56/2 = 28 m2

7 x 8 = 56/2 = 28 m2

___________________

Total Surface Area = 120 m2

a of a triangle = base x height divided by 2

a of rectangle = length x width

8 x 4.5 = 36 m2

8 x 4.5 = 36 m2

8 x 6 = 48 m2

6 x 3.35 = 20.1/2 = 10.5

6 x 3.35 = 20.1/2 = 10.5

_____________________

Total Surface Area = 140.1 m2

4. Ty is painting this storage bench for the deck.

How much area does he need to paint, to the nearest

hundredth of a square meter?

length x width = a

S- 0.38 x 0.5 = 0.19 m2

- 0.38 x 0.5 = 0.19 m2

F- 0.5 x 1.56 = 0.78 m2

- 0.5 x 1.56 = 0.78 m2

T- 1.56 x 0.38 = 0.5928 m2

- 1.56 x 0.38 = 0.5928 m2

________________________

= 3.1256 round up...

Total Surface Area = 3.13 m2

Cylinder Volume and Volume Problems




r = d / 2…………………….v = π.r.r.h asdfghjkl;………….502.4m3^ / 2 = 251.2m3^
r = 8 /2……………………..v = (3.14 x 4 x 4) x 10
r = 4m……………………….v = 50.24 m2^ x 10m
…….asdfghjkl;…………….v = 502.4 m3^





r = d / 2.......................v = π.r.r.h

r = 80 / 2……………….v = (3.14 x 40 x 40) x 45

r = 40cm……..….……..v = 5024 cm2^ x 45cm
……………………………..v = 226,080cm3^

226,080 / 80 = 2826cm2^

2826 / 3.14 = 900cm

√900 = 30cm

30 x 2 = 60cm -diameter