Question

Use the formula for the volume of a sphere to find the volume of a basketball that has a diameter of 9.2 inches. Use 3.14 as an approximation for pi and round your answer to the nearest hundredth, if necessary.
Find the volume of a sphere with a radius of 1.8 yards. Leave your answer in terms of pi. Round your answer to the nearest hundredth, if necessary.
Use the formula for the volume of a sphere to solve the following problem.
How much air is needed to fill a basketball with a diameter of 9 inches? Use 3.14 as an approximation for pi. Round your answer to the nearest tenth.
The volume of a container measures 4,000 mm3
and contains 50 marbles. Each marble has a radius of 2 mm. Use 3.14 as an approximation for pi. How much space in the box is unused? Round your answer to the nearest tenth.
Kairay created a sculpture by forming a hemisphere with a radius of 20 inches and then removing a hemisphere with a radius of 15 inches from it. Calculate the volume of his sculpture. Use 3.14 as an approximation for pi. Round your answer to the nearest whole number.

Answers

GPT-4o mini
To calculate the volumes requested using the formula for the volume of a sphere, we will use the formula:

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

where \( r \) is the radius of the sphere.

### 1. Volume of a basketball with a diameter of 9.2 inches

First, we find the radius:

\[
r = \frac{diameter}{2} = \frac{9.2}{2} = 4.6 \text{ inches}
\]

Now we use the volume formula:

\[
V = \frac{4}{3} \pi (4.6)^3
\]

Calculating \( (4.6)^3 \):

\[
(4.6)^3 = 97.336
\]

Now substituting back into the volume formula:

\[
V = \frac{4}{3} \times 3.14 \times 97.336
\]

Calculating \( \frac{4}{3} \):

\[
\frac{4}{3} \approx 1.3333
\]

Now calculating the volume:

\[
V \approx 1.3333 \times 3.14 \times 97.336 \approx 406.193
\]

Rounding to the nearest hundredth:

\[
\text{Volume} \approx 406.19 \text{ cubic inches}
\]

### 2. Volume of a sphere with a radius of 1.8 yards

Using the volume formula:

\[
V = \frac{4}{3} \pi (1.8)^3
\]

Calculating \( (1.8)^3 \):

\[
(1.8)^3 = 5.832
\]

So, the volume is:

\[
V = \frac{4}{3} \pi (5.832) = \frac{4 \cdot 5.832}{3} \pi
\]

Calculating:

\[
\frac{4 \cdot 5.832}{3} = 7.776
\]

Thus, the volume in terms of \( \pi \) is:

\[
V \approx 7.776\pi \text{ cubic yards}
\]

### 3. How much air is needed to fill a basketball with a diameter of 9 inches?

First, we find the radius:

\[
r = \frac{9}{2} = 4.5 \text{ inches}
\]

Now apply the volume formula:

\[
V = \frac{4}{3} \pi (4.5)^3
\]

Calculating \( (4.5)^3 \):

\[
(4.5)^3 = 91.125
\]

Thus, the volume is:

\[
V = \frac{4}{3} \times 3.14 \times 91.125 \approx 381.696
\]

Rounding to the nearest tenth:

\[
\text{Volume} \approx 381.7 \text{ cubic inches}
\]

### 4. Unused space in a box that measures 4,000 mm³ containing 50 marbles with a radius of 2 mm

First, find the volume of one marble:

Using the volume formula:

\[
V = \frac{4}{3} \pi (2)^3
\]

Calculating \( (2)^3 = 8 \):

\[
V = \frac{4}{3} \pi (8) = \frac{32}{3} \pi \approx 33.51 \text{ mm}^3
\]

Now for 50 marbles:

\[
50 \cdot \frac{32}{3} \approx 50 \cdot 33.51 \approx 1675.5 \text{ mm}^3
\]

Calculating unused space:

\[
\text{Unused space} = 4000 - 1675.5 \approx 2324.5
\]

Rounding to the nearest tenth:

\[
\text{Unused space} \approx 2324.5 \text{ mm}^3
\]

### 5. Volume of Kairay’s sculpture

Calculating the volume of the large hemisphere with a radius of 20 inches:

\[
V_{large} = \frac{2}{3} \pi (20)^3
\]

Calculating \( (20)^3 = 8000 \):

\[
V_{large} = \frac{2}{3} \times 3.14 \times 8000 \approx 16758.67 \text{ cubic inches}
\]

Now for the small hemisphere with a radius of 15 inches:

\[
V_{small} = \frac{2}{3} \pi (15)^3
\]

Calculating \( (15)^3 = 3375 \):

\[
V_{small} = \frac{2}{3} \times 3.14 \times 3375 \approx 7068.75 \text{ cubic inches}
\]

Now finding the volume of the sculpture:

\[
V_{sculpture} = V_{large} - V_{small} \approx 16758.67 - 7068.75 \approx 9689.92
\]

Rounding to the nearest whole number:

\[
\text{Volume of sculpture} \approx 9690 \text{ cubic inches}
\]

In summary:
1. Volume of the basketball: 406.19 cubic inches
2. Volume of sphere in terms of \( \pi \): \( 7.776\pi \) cubic yards
3. Air needed for filling basketball: 381.7 cubic inches
4. Unused space in box: 2324.5 mm³
5. Volume of Kairay's sculpture: 9690 cubic inches