Cones, Cylinders, & Spheres Unit Test

14 of 1514 of 15 Items

Question
The volume of a sphere is 48 m3
. What is the volume of a cylinder if its radius is the same as the sphere’s and its height is equal to the sphere’s diameter?(1 point)

1 answer

To solve the problem, we need to use the formulas for the volume of a sphere and the volume of a cylinder.

  1. Volume of a sphere: \[ V = \frac{4}{3} \pi r^3 \] Given the volume of the sphere \( V = 48 , m^3 \), we can set up the equation: \[ \frac{4}{3} \pi r^3 = 48 \] To find \( r \), we first isolate \( r^3 \): \[ r^3 = \frac{48 \times 3}{4\pi} = \frac{144}{4\pi} = \frac{36}{\pi} \]

  2. Calculating the radius: \[ r = \left(\frac{36}{\pi}\right)^{\frac{1}{3}} \]

  3. Diameter of the sphere: The diameter \( d \) of the sphere is: \[ d = 2r \]

  4. Volume of the cylinder: The formula for the volume of a cylinder is: \[ V = \pi r^2 h \] Here, the height \( h \) of the cylinder is equal to the diameter of the sphere: \[ h = 2r \] Now we can substitute \( h \) into the cylinder volume formula: \[ V = \pi r^2 (2r) = 2\pi r^3 \]

  5. Substituting for \( r^3 \): From our earlier calculation, we found that \( r^3 = \frac{36}{\pi} \): \[ V = 2\pi \left(\frac{36}{\pi}\right) = 2 \times 36 = 72 , m^3 \]

Thus, the volume of the cylinder is 72 m³.