Need help with two math questions:

1. A brand new filled can of chicken broth is 10 cm tall and has a radius of 10 cm. Mishka uses some of the broth to cook and now the broth left in the can is 6 cm high. How much broth did Mishka use?

A) 943 cm³
B) 1257 cm³
C) 1885 cm³
D) 4712 cm³

2. A cone with volume 1350 m³ is dilated by a scale factor of 1/3. What is the volume of the resulting cone?



Thanks to anyone who helps!

Respuesta :

Answers: 1:B, 2:450

How-To:

Using the formula for area on the bottom of the can, (pi*r^2) you can then multiply by the amount of height missing, which is 4.

Since it was originally 10, you subtract 4 in order to get 6.

That's how to get 4.

Now, plug in pi*r^2 into a calculator (or if you must work it out, radius, r, is 10, so 10*10 is 100. 100*3.14159265 is 314.159265

Now multiply 314 by the height missing (4) to get approximately 1257.



Now for number 2.
It says it is dilated by a scale factor of 1:3 (from 1350). That means that it was made smaller, (that's what dilated means) by 3 for every 1. So take 1350 and divide it by 3 to get 450

Answer:

Part 1) Option B  [tex]1,257\ cm^{3}[/tex]

Part 2) The volume of the resulting cone is [tex]50\ cm^{3}[/tex]

Step-by-step explanation:

Part 1)

Find the volume of the can

The volume of the cylinder (can) is equal to

[tex]V=\pi r^{2}h[/tex]

we have

[tex]r=10\ cm[/tex]

[tex]h=10\ cm[/tex]

substitute

[tex]V=\pi (10^{2})(10)=1,000 \pi\ cm^{3}[/tex]

Remember that

For [tex]h=10\ cm[/tex] subtends a volume of [tex]V=1,000 \pi\ cm^{3}[/tex]

so

by proportion

Find the volume for [tex]h=10-6=4\ cm[/tex]

[tex]\frac{1,000\pi }{10}=\frac{x}{4}\\ \\x=1,000\pi *4/10\\ \\x=400\pi \\ \\x=1,257\ cm^{3}[/tex]

Part 2)

we know that

If two figures are similar, then the ratio of its volumes is equal to the scale factor elevated to the cube

Let

z----> the scale factor

x-----> the volume of the resulting cone

y-----> the volume of the original cone

so

[tex]z^{3}=\frac{x}{y}[/tex]

in this problem we have

[tex]z=1/3[/tex]

[tex]y=1,350\ cm^{3}[/tex]

substitute and solve for x

[tex](1/3)^{3}=\frac{x}{1,350}[/tex]

[tex](1/27)=\frac{x}{1,350}[/tex]

[tex]x=1,350*(1/27)=50\ cm^{3}[/tex]

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