A cone is placed inside a cylinder. The cone has half the radius of the cylinder, but the height of each figure is the same. The cone is tilted at an angle so its peak touches the edge of the cylinder's base. What is the volume of the space remaining in the cylinder after the cone is placed inside it?

A. [tex]\frac{3}{4} \pi r^2 h[/tex]
B. [tex]\frac{2}{3} \pi r^2 h[/tex]
C. [tex]\frac{11}{12} \pi r^2 h[/tex]
D. [tex]\frac{5}{6} \pi r^2 h[/tex]
E. [tex]\frac{1}{2} \pi r^2 h[/tex]



Answer :

Let's determine the volume of the space remaining in the cylinder after placing the cone inside it.

First, let's consider the two figures separately:

1. Volume of the Cylinder:
The formula for the volume of a cylinder is given by [tex]\( V_{\text{cylinder}} = \pi r^2 h \)[/tex], where [tex]\( r \)[/tex] is the radius of the cylinder and [tex]\( h \)[/tex] is the height of the cylinder.

2. Volume of the Cone:
The formula for the volume of a cone is given by [tex]\( V_{\text{cone}} = \frac{1}{3} \pi r_{\text{cone}}^2 h \)[/tex], where [tex]\( r_{\text{cone}} \)[/tex] is the radius of the base of the cone and [tex]\( h \)[/tex] is the height of the cone.

Given that the radius of the cone is half the radius of the cylinder, we have:
[tex]\[ r_{\text{cone}} = \frac{r}{2} \][/tex]

Now we can express the volume of the cone as:
[tex]\[ V_{\text{cone}} = \frac{1}{3} \pi \left(\frac{r}{2}\right)^2 h \][/tex]
[tex]\[ V_{\text{cone}} = \frac{1}{3} \pi \left( \frac{r^2}{4} \right) h \][/tex]
[tex]\[ V_{\text{cone}} = \frac{1}{3} \cdot \frac{\pi r^2 h}{4} \][/tex]
[tex]\[ V_{\text{cone}} = \frac{1}{12} \pi r^2 h \][/tex]

Next, to find the volume of the space remaining in the cylinder after placing the cone inside it, we subtract the volume of the cone from the volume of the cylinder:
[tex]\[ \text{Remaining Volume} = V_{\text{cylinder}} - V_{\text{cone}} \][/tex]
[tex]\[ \text{Remaining Volume} = \pi r^2 h - \frac{1}{12} \pi r^2 h \][/tex]
[tex]\[ \text{Remaining Volume} = \pi r^2 h \left(1 - \frac{1}{12}\right) \][/tex]
[tex]\[ \text{Remaining Volume} = \pi r^2 h \left(\frac{12}{12} - \frac{1}{12}\right) \][/tex]
[tex]\[ \text{Remaining Volume} = \pi r^2 h \cdot \frac{11}{12} \][/tex]
[tex]\[ \text{Remaining Volume} = \frac{11}{12} \pi r^2 h \][/tex]

Therefore, the volume of the space remaining in the cylinder after placing the cone is:

[tex]\[ \boxed{\frac{11}{12} \pi r^2 h} \][/tex]