Please help me! Will give medal :)
The volume of a cone is 300 cubic kilometers. If the radius of the base is 7 kilometers, what is the height of the cone? Use three point one four for pi. Show your work and round to the nearest tenth.

Question

Please help me! Will give medal :)
The volume of a cone is 300  cubic kilometers. If the radius of the base is 7 kilometers, what is the height of the cone? Use three point one four for pi. Show your work and round to the nearest tenth.

anonymous · Answer

Please help! last question for my final exam... :)

anonymous · Answer

@nincompoop

nincompoop · Answer

do you know the formula of the volume of a cone?

nincompoop · Answer

$$V=\pi r^2 \frac{ h }{ 3 }$$

anonymous · Answer

i was just gonna write that lol

nincompoop · Answer

so solve for h 
$$\frac{ 3V }{ \pi r^2 }=h$$

anonymous · Answer

V = πr^2h 
300 km^3 = 3.14(7 km)^2 h 
1.949824516... = h 

The height is approximately 1.9 km

nincompoop · Answer

$$\frac{ 3\times 300 }{ \pi \times 7^2 }$$

nincompoop · Answer

neroye, please do not give out answers. it is a violation of the code of conduct

anonymous · Answer

3*300=900... 3.14*49=153.86

nincompoop · Answer

did you use a calculator? it says nearest tenth

anonymous · Answer

yes i used calculator.. my teacher says i can.. :)

anonymous · Answer

so 154

nincompoop · Answer

http://hotmath.com/hotmath_help/topics/rounding-decimals/place-value.gif

anonymous · Answer

153 or 154.. i think its 153

nincompoop · Answer

nope

nincompoop · Answer

did you look at the place values?

anonymous · Answer

yes

anonymous · Answer

i reccommed not use a calculator it will ruin your math 
just an advice

anonymous · Answer

gotya chief :)

nincompoop · Answer

12345.6789

nearest tenth would be looking at the 6 
and you have to look at the number to its right. if it is 5 or more you add 1 to 6

anonymous · Answer

you know how to round off right?

nincompoop · Answer

so that gives you 
12345.7 as nearest tenth round off

nincompoop · Answer

@ChiefArnav I got this already. you can help other people

anonymous · Answer

i'am justing a job from my part know u didi it but 
i hiope u got me

anonymous · Answer

150.9

anonymous · Answer

do u want a re expalination

anonymous · Answer

umm.. its ok @nincompoop can help me :) thanks for your help though..

anonymous · Answer

okay

nincompoop · Answer

correct

anonymous · Answer

ok... so is that all?

nincompoop · Answer

yeah

anonymous · Answer

may be guess so

nincompoop · Answer

we've done a formula transformation
that is we first determined the formula of h in a volume of a cone
then use that formula to solve for the actual value with the information we were provided.

anonymous · Answer

got it! thank you all so much!

nincompoop · Answer

you're welcome