39,517 views
1 vote
1 vote
I need help please. A cone with a height of 15 mm has a volume of approximately 15.7 mm cubed. To the nearest whole number, what is the diameter of the cone?

User Megs
by
3.2k points

1 Answer

21 votes
21 votes

The volume formula for a circular cone is


V=(1)/(3)\pi(r)^2h

Where h = 15 and V = 15.7, let's replace this information and solve for r


\begin{gathered} 15.7=(1)/(3)\cdot\pi\cdot(r)^2\cdot15 \\ 15.7=15.71r^2 \\ r=\sqrt[]{(15.7)/(15.71)} \\ r\approx1 \end{gathered}

If the radius is 1 mm, then the diameter is 2 because it must be double.

Hence, the diameter measures 2 mm.

User Yury Finchenko
by
2.5k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.