Volumes by disks

Answer Key - Grade 12 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Ari spins the region under y = 2x, 0 ≤ x ≤ 3, about the x-axis to make a cone. Write the volume as V = kπ. What is k?

   36
2. 2.

   Bo spins the region under y = 3x, 0 ≤ x ≤ 2, about the x-axis to make a cone. Write the volume as V = kπ. What is k?

   24
3. 3.

   Esme spins the region under y = 2x, 0 ≤ x ≤ 6, about the x-axis to make a cone. Write the volume as V = kπ. What is k?

   288
4. 4.

   Jun spins the region under y = 4x, 0 ≤ x ≤ 3, about the x-axis to make a cone. Write the volume as V = kπ. What is k?

   144
5. 5.

   Kira spins the region under y = √x, 0 ≤ x ≤ 4, about the x-axis. Write the volume as V = kπ. What is k?

   8
6. 6.

   Luz spins the region under y = √x, 0 ≤ x ≤ 9, about the x-axis. Write the volume as V = kπ. What is k?

   81/2
7. 7.

   Milo spins the region under y = √x, 0 ≤ x ≤ 16, about the x-axis. Write the volume as V = kπ. What is k?

   128
8. 8.

   Noah spins the region under y = √x, 0 ≤ x ≤ 1, about the x-axis. Write the volume as V = kπ. What is k?

   1/2
9. 9.

   Tala spins the region under y = 2x², 0 ≤ x ≤ 2, about the x-axis. Write the volume as V = kπ. What is k?

   128/5
10. 10.

    Zee spins the region under y = 4x², 0 ≤ x ≤ 1, about the x-axis. Write the volume as V = kπ. What is k?

    16/5