Posted by simran on Tuesday, December 4, 2012 at 6:35am.
A Toy is in the form of a hemisphere surmounted by a right circular cone of the same base radius as that of the hemisphere .If the radius of base of the cone is 21 cm and its volume is 2/3 of the volume of hemisphere calculate the height of cine and surface area of the toy.

maths  Reiny, Tuesday, December 4, 2012 at 8:19am
The missing part is the height of the cone, but it is 2/3 the volume of the hemisphere (semisphere).
volume of hemisphere = (1/2 (4/3)π (21^3) = 6174π
but the volume of the cone is 2/3 of that or 4116π
vol of cone = (1/3)π r^2 h
4116π = (1/3)π(21^2)h
12348 = 441h
h = 28
Now use your formulas for surface area of a sphere, take half of that , and use your formula for the surface area of a cone with radius 21 and height 28
Make sure NOT to include the circular base joining them when finding surface area
Answer This Question
Related Questions
 math  A right circular cone stands on a hemisphere. The base radius of the cone...
 mathssurface area  A solid is in the form of cone mounted on a hemisphere in ...
 Math  Please Help A body consists of a solid hemisphere of radius r joined to a...
 Math  a cone and a hemisphere share the base that is a semicirclee with radius ...
 Calculus  Given a right circular cone, you put an upsidedown cone inside it so...
 math  Two right circular cone, one upside down in the other. The two bases are ...
 Calculus: Optimization  I have no idea how to approach this problem, if someone...
 Math 214  How do you find the volume of a right circular cone with a hemisphere...
 AP Calculus..again  A balloon is composed of a right circular cone joined at ...
 geometry  A cone is topped with a hemisphere. Calculate the total surface area ...
More Related Questions