SOLUTION: A cylindrical rod of length "h" is melted and cast into a cone of base radius twice that one of the cylinder. What is the height of the cone??.. please reply... THANKYOU VERY MUCH

Algebra ->  Volume -> SOLUTION: A cylindrical rod of length "h" is melted and cast into a cone of base radius twice that one of the cylinder. What is the height of the cone??.. please reply... THANKYOU VERY MUCH      Log On


   



Question 923588: A cylindrical rod of length "h" is melted and cast into a cone of base radius twice that one of the cylinder. What is the height of the cone??.. please reply... THANKYOU VERY MUCH
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
volume(V) of the cylinder is pi*r^2*h
volume(V) of the cone is (1/3)*pi*(2r)^2*hc where hc is height of cone
volumes are the same so set equations equal to each other
pi*r^2*h = (1/3)*pi*(2r)^2*hc
pi*r^2*h = (1/3)*pi*4r^2*hc
cancel what we can from both sides of =
h = (1/3)*4*hc
multiply both sides of = by 3
3h = 4*hc
hc = 3h/4
therefore the height of the cone is 3/4 of the height of the cylinder