Question

Suppose that a sphere with radius 5a has the same volume as a cone of radius 3a. What is the height of the cone? Give your answer in terms of a. Use the formulas of A and B for the volumes of a sphere and cone respectively.

Formula A: http://i1255.photobucket.com/albums/hh639/zigzagoon20001/FormulaA.jpg

Formula B: http://i1255.photobucket.com/albums/hh639/zigzagoon20001/FormulaB.jpg

A. 9/500a

B. 500/9a^2

C. 9/500a^2

D. 500/9a

A, B, C, or D? Please explain (:

Answer 1

Volume of the sphere=4/3*pi*r^3
=4/3*pi*(5a)^3
=4/3*pi*125(a^3)
Volume of the cone=1/3*pi*r^2*h
=1/3*pi*(3a)^2*h
=1/3*pi*9*(a^2)*h
It is given that the volumes are equal. so
4/3*pi*125(a^3)=1/3*pi*9*(a^2)*h
Solve the equation for h. can u do it @zigzagoon2000?

Answer 2

I'm sorry, I can't.

Answer 3

Do u understand vat I have done?

Answer 4

@zigzagoon2000

Answer 5

or u want me to explain it? if u r nt clear plz ask:)