Sophia is setting up two fish tanks for her pet fish. One tank is a rectangular prism, and the other is a cylinder. She needs to determine which tank will hold more water so she can put her larger fish in the tank with more volume.

The rectangular prism tank has a length of 30 cm, a width of 20 cm, and a height of 50 cm.

The cylindrical tank has a radius of 15 cm and a height of 50 cm.

Your task:

1. Calculate the volume of each fish tank.

2. Compare the volumes of the two tanks to figure out which one holds more water.

3. Show all your work, including the formulas you use for calculating the volume of both shapes.

4. Based on your calculations, which tank should hold the bigger fish?

(4 points)

1 answer

To determine which fish tank holds more water, we need to calculate the volume of each tank using the appropriate formulas.

1. Calculate the Volume

A. Volume of the Rectangular Prism Tank

The formula for the volume \( V \) of a rectangular prism is: \[ V = \text{length} \times \text{width} \times \text{height} \]

Given:

  • Length = 30 cm
  • Width = 20 cm
  • Height = 50 cm

Now substitute the values into the formula: \[ V = 30 , \text{cm} \times 20 , \text{cm} \times 50 , \text{cm} \]

Calculating: \[ V = 30 \times 20 = 600 , \text{cm}^2 \] \[ V = 600 , \text{cm}^2 \times 50 , \text{cm} = 30000 , \text{cm}^3 \]

Thus, the volume of the rectangular prism tank is 30,000 cm³.

B. Volume of the Cylindrical Tank

The formula for the volume \( V \) of a cylinder is: \[ V = \pi r^2 h \]

Given:

  • Radius \( r = 15 , \text{cm} \)
  • Height \( h = 50 , \text{cm} \)

Now substitute the values into the formula: \[ V = \pi (15 , \text{cm})^2 (50 , \text{cm}) \] Calculating \( (15 , \text{cm})^2 \): \[ (15 , \text{cm})^2 = 225 , \text{cm}^2 \]

Now substitute: \[ V = \pi \times 225 , \text{cm}^2 \times 50 , \text{cm} \] \[ V = \pi \times 11250 , \text{cm}^3 \]

Using \( \pi \approx 3.14 \): \[ V \approx 3.14 \times 11250 , \text{cm}^3 \approx 35325 , \text{cm}^3 \]

Thus, the volume of the cylindrical tank is approximately 35,325 cm³.

2. Compare the Volumes

Now we will compare the volumes of both tanks:

  • Rectangular Prism Volume: 30,000 cm³
  • Cylindrical Tank Volume: 35,325 cm³

3. Conclusion

The cylindrical tank has a greater volume of approximately 35,325 cm³, compared to the rectangular prism tank which holds 30,000 cm³.

4. Bigger Fish Tank

Based on the calculations, the cylindrical tank should hold the bigger fish since it has a greater volume.