To find the volume of a hemisphere, we can use the formula for the volume of a sphere, which is:
\[ V = \frac{4}{3} \pi r^3 \]
Since a hemisphere is half of a sphere, the volume of the hemisphere can be calculated using:
\[ V = \frac{1}{2} \times \frac{4}{3} \pi r^3 = \frac{2}{3} \pi r^3 \]
First, we need to find the radius \( r \) from the diameter. The diameter is given as 10.2 inches, so the radius is:
\[ r = \frac{d}{2} = \frac{10.2}{2} = 5.1 \text{ inches} \]
Now, we can plug the radius into the hemisphere volume formula:
\[ V = \frac{2}{3} \pi (5.1)^3 \]
Calculating \( (5.1)^3 \):
\[ (5.1)^3 = 5.1 \times 5.1 \times 5.1 = 132.651 \text{ cubic inches} \]
Now substituting this back into our volume formula:
\[ V = \frac{2}{3} \times 3.14 \times 132.651 \]
Calculating this step-by-step:
- First, calculate \( \frac{2}{3} \times 3.14 \):
\[ \frac{2}{3} \times 3.14 \approx 2.0933 \]
- Now, multiply by \( 132.651 \):
\[ V \approx 2.0933 \times 132.651 \approx 277.67 \text{ cubic inches} \]
- Rounding to the nearest whole number, we get:
\[ V \approx 278 \text{ cubic inches} \]
So the answer is:
278 in.³