Tuesday, February 15, 2011

Paul's Textbook post

Show you know pg. 248 and 249
Questions 1,3,7 pg. 250-253

Show you know
pg.248

V=area of base x height

V=40cm² x 22cm

V=880cm³

pg. 249

Left

V=area of base x height
V=24cm² x 7cm

V=168cm³
Right
V=area of base x height
V=56cm² x 3cm
V=168cm³
Both has the same volume

Question 1

In their calculation Charlotte made a mistake measuring the right rectangular prism because she did not use the prism's height.
Instead she should have done this.
V=area of base x height
V=63cm² x 3cm

V=189cm³

Question 3

A)

V=area of base x height
V=15cm² x 4cm
V=60cm³
B)
V=area of base x height

V=18cm² x 4cm
V=216cm³
C)
V=area of base x height
V=96cm² x 20cm
V=1920cm³

Question 7

a)
h=volume divided by area of base
h=32cm³ divided by 8cm²
h=4cm
b)
h=volume divided by area of base
h=35cm³ divided by 5cm²
h=7cm
c)
h=volume divided by area of base
h=36cm³ divided by 9cm²
h=4cm

Here's a link on how to find the volume of a cylinder and a right rectangular prism.

Cylinder

Right rectangular prism

Cylinder Volume and Volume Problems
7.3

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

v=(π.r.r).h
v=(3.14x10x10)x40
v=314x40
v=12 560cm³

Popcorn Lover's
r=d/2
r=30/2
r=15cm

v=(π.r.r).h
v=(3.14x15x15)x20
v=706.5x20
v=14 130cm³
Martha should choose popcorn lover's conatiner because it has more volume than the jumbo container.

7.4

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

v=(π.r.r).h
v=(3.14x60x60)x18

v=11 304x18
v=203 472cm³

b)v=lxwxh
v=30x22x20
v=13 200cm³

c)volume of wading pool / volume of pail
203 472 / 13 200= 15.4 pails of water

Volume of cylinder