A sandcastle mold is in the shape of a cone, with a diameter of 4

meters and a height of 6 meters. What volume of sand is needed
to fill the mold? Use 3.14 for π. (1 point)
75.36 cubic meters
25.12 cubic meters
100.48 cubic meters
150.72 cubic meters

1 answer

To find the volume of the sandcastle mold, which is in the shape of a cone, we can use the formula for the volume of a cone:

\[ V = \frac{1}{3} \pi r^2 h \]

Where:

  • \( V \) is the volume,
  • \( r \) is the radius of the base of the cone,
  • \( h \) is the height of the cone.
  1. First, we need to find the radius. The diameter is given as 4 meters, so the radius \( r \) is:

\[ r = \frac{\text{diameter}}{2} = \frac{4}{2} = 2 \text{ meters} \]

  1. The height \( h \) of the cone is given as 6 meters.

  2. Now, we can substitute the values into the volume formula:

\[ V = \frac{1}{3} \times 3.14 \times (2)^2 \times 6 \]

  1. Calculate \( (2)^2 \):

\[ (2)^2 = 4 \]

  1. Substitute this back into the equation:

\[ V = \frac{1}{3} \times 3.14 \times 4 \times 6 \]

  1. Calculate \( 4 \times 6 \):

\[ 4 \times 6 = 24 \]

  1. Now, substitute and calculate:

\[ V = \frac{1}{3} \times 3.14 \times 24 \]

  1. Calculate \( 3.14 \times 24 \):

\[ 3.14 \times 24 = 75.36 \]

  1. Finally, divide by 3:

\[ V = \frac{75.36}{3} = 25.12 \]

Thus, the volume of sand needed to fill the mold is:

\[ \boxed{25.12} \text{ cubic meters} \]