a circular cone has an altitude of 6 meters. the volume of the cone is 12(3.14) cubic meters. what is the radius of the cone?
2007-01-31 10:53:25 · 6 answers · asked by argentina_mandy20 1 in Science & Mathematics ➔ Mathematics
volume of cone = 1/3*h*pi*r^2
12Pi=1/3*6*Pi*r^2
12=2r^2
6=r^2
r=sqrt(6)
r=2.44meters
2007-01-31 10:58:51 · answer #1 · answered by bruinfan 7 · 1⤊ 0⤋
The volume of a cone is:
1/3 h*A where h=height and A= area of base.
Since a cone has a circular base, A = r^2 * pi
so...
12 pi = 1/3 * 6 * r^2 * pi
12 = 2 r^2
6 = r^2
r = 6^1/2 or the square root of 6 which is approximately 2.4495 meters
Hope this helps!
2007-01-31 19:02:52 · answer #2 · answered by disposable_hero_too 6 · 1⤊ 0⤋
To find the volume of a cone, you use V=1/3Ïr^2h.
So 12(3.14)=1/3(3.14)6r^2
37.68=6.28r^2
6=r^2
sqrt6=sqrtr^2
2.44948974=r
Note: The answer is a tiny fraction off, due to the fact that pi was approximated.
2007-01-31 19:22:26 · answer #3 · answered by Orion 2 · 0⤊ 0⤋
As I recall the formula for the volume of a cone is 1/3 (pi * r *r * h)
so....substituting everything you get
12 * 3.14 = ((3.14) (r) (r) * 6 ) / 3
simplifying by cancelling the value of Pi and dividing the 6 by 3 you get
12= (r) (r) (2)
or
r squared = 6 (wish I new how to make a square or sq. rt. symbol)
r = square root of 6
2007-01-31 19:08:07 · answer #4 · answered by ca_surveyor 7 · 0⤊ 0⤋
3
2007-01-31 18:57:55 · answer #5 · answered by cooling1981 3 · 0⤊ 3⤋
The formula for a cone according to this little math booklet I found is; V= (1/3)3.14 r^2 (h).
You already have V or Volume and height or "altitude".
37.68 = (1/3) 3.14 r^2(6m). So, r = V (1/3) 3.14/ 6h
r = 6.57. I got 41.25 in the final answer. So, 41.25 -37.68 = 4.2. So, 6.57- 4.2= 2.36. So, that's my answer. Don't forget to square root it. Which is; 1.53.
2007-01-31 21:13:21 · answer #6 · answered by sandwreckoner 4 · 0⤊ 0⤋