If the cylinder and the cone shown have the same volume, then the radius and height of the cone could be which of these? (2 points) Responses radius of the cone = 5; height of the cone = 12 radius of the cone = 5; height of the cone = 12 radius of the cone = 15; height of the cone = 12 radius of the cone = 15; height of the cone = 12 radius of the cone = 5; height of the cone = 4 radius of the cone = 5; height of the cone = 4 radius of the cone = 15; height of the cone = 4 radius of the cone = 15; height of the cone = 4 Skip to navigation

1 answer

To determine which combination of radius and height for the cone will result in the same volume as the cylinder, we need to use the formula for the volume of a cylinder and a cone.

The volume of a cylinder is given by V_cylinder = πr^2h, where r is the radius of the cylinder and h is the height of the cylinder.

The volume of a cone is given by V_cone = (1/3)πr^2h, where r is the radius of the cone and h is the height of the cone.

Since the volume of the cylinder and the cone are equal, we can set up the following equation:

πr_cylinder^2h_cylinder = (1/3)πr_cone^2h_cone

Canceling out the common factor of π and rearranging the equation, we get:

3r_cylinder^2h_cylinder = r_cone^2h_cone

Given that the radius of the cylinder is equal to 5 units (r_cylinder = 5 in this case) and the height of the cylinder is 12 units (h_cylinder = 12), we can substitute these values into the equation to solve for the radius and height of the cone.

3(5)^2(12) = r_cone^2h_cone

3(25)(12) = r_cone^2h_cone

900 = r_cone^2h_cone

Now we need to look at the given options for the radius and height of the cone:

1. radius of the cone = 5; height of the cone = 12
2. radius of the cone = 15; height of the cone = 12
3. radius of the cone = 5; height of the cone = 4
4. radius of the cone = 15; height of the cone = 4

Substitute the values of radius and height in each option into the equation to determine if it results in 900:

For option 1: (5)^2(12) = 300 (not equal to 900)
For option 2: (15)^2(12) = 2700 (not equal to 900)
For option 3: (5)^2(4) = 100 (not equal to 900)
For option 4: (15)^2(4) = 900 (equal to 900)

Therefore, the correct combination of radius and height for the cone is: radius of the cone = 15; height of the cone = 4