SOLUTION: Tony needs a glass bell jar in the shape of a cylinder with a hemisphere on top. The height of the cylinder must be 3 inches longer than its radius and the volume must be 72pi cubi

Algebra.Com
Question 265854: Tony needs a glass bell jar in the shape of a cylinder with a hemisphere on top. The height of the cylinder must be 3 inches longer than its radius and the volume must be 72pi cubic inches. What should the radius of the cylinder be?
The name of the lesson is Fundamental Theorem of Algebra.
Do i need to find the roots to get the radius?

Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
Tony needs a glass bell jar in the shape of a cylinder with a hemisphere on top. The height of the cylinder must be 3 inches longer than its radius and the volume must be 72pi cubic inches. What should the radius of the cylinder be?
:
Let r = the radius of the cylinder (and the hemisphere)
then
(r+3) = the height of the cylinder
:
vol of a sphere =, therefore
vol of a hemisphere =
:
vol of cylinder + vol of hemisphere = 72*pi
+ =
:
Divide thru by pi and eliminate that
+ = 72
:
Replace h with (r+3)
+ = 72
:
+ = 72
:
Add like terms r^3 + 2/3*r^3
+ = 72
:
Multiply each term by 3
= 216
:
= 0
:
Graph this equation, find x intercept

r = 3 inches the radius
:
Check; find the volumes
= 169.646
= 56.487
--------------------
Total volume is 226.195 divide this by pi you have 71.999 ~ 72

RELATED QUESTIONS

for a scietific experiment, Tony needs a glass bell jar in the shape of a cylinder with a (answered by lwsshak3)
A large grain silo is to be constructed in the shape of a circular cylinder with a... (answered by josgarithmetic,greenestamps)
A silo consists of a right circular cylinder with a hemisphere on top. The radius of the... (answered by ankor@dixie-net.com)
A figure is a cylinder with a radius of 6 inches and a height of 10 inches. On top of the (answered by ewatrrr)
A large grain silo is to be constructed in the shape of a circular cylinder with a... (answered by mananth)
A large grain silo is to be constructed in the shape of a circular cylinder with a... (answered by Jc0110)
A large grain silo is to be constructed in the shape of a circular cylinder with a... (answered by ankor@dixie-net.com)
A large grain silo is to be constructed in the shape of a circular cylinder with a... (answered by josgarithmetic)
how do you calculate the surface area of a right cylinder topped with a hemisphere, if... (answered by ewatrrr)