Question

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?

Answer 1

The volume formula for a circular cone is

$V=\frac{1}{3}\pi(r)^2h$

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

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

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

Hence, the diameter measures 2 mm.