The volume of a sphere is 72 m3 . What is the volume of a cone if its radius is the same as the sphere’s and its height is equal to the sphere’s diameter?(1 point

1 answer

The volume \( V \) of a sphere is given by the formula:

\[ V = \frac{4}{3} \pi r^3 \]

Given that the volume of the sphere is \( 72 , \text{m}^3 \), we can set up the equation:

\[ 72 = \frac{4}{3} \pi r^3 \]

To find the radius \( r \), we can solve for \( r^3 \):

\[ r^3 = \frac{72 \times 3}{4\pi} = \frac{216}{4\pi} = \frac{54}{\pi} \]

Now, we calculate the radius:

\[ r = \left( \frac{54}{\pi} \right)^{1/3} \]

Next, we need to calculate the volume of the cone, which is given by the formula:

\[ V_{\text{cone}} = \frac{1}{3} \pi r^2 h \]

The height \( h \) of the cone is equal to the diameter of the sphere, which is \( 2r \):

\[ h = 2r \]

Now substituting \( h \) into the volume formula for the cone:

\[ V_{\text{cone}} = \frac{1}{3} \pi r^2 (2r) = \frac{2}{3} \pi r^3 \]

We know \( r^3 = \frac{54}{\pi} \), so substituting that into the volume of the cone gives:

\[ V_{\text{cone}} = \frac{2}{3} \pi \left( \frac{54}{\pi} \right) = \frac{2 \times 54}{3} = \frac{108}{3} = 36 \]

Thus, the volume of the cone is \( 36 , \text{m}^3 \).

So, the final answer is:

\[ \text{Volume of the cone} = 36 , \text{m}^3 \]