Select the correct answer.

The shape of a capsule consists of a cylinder with identical hemispheres on each end. The diameter of the hemispheres is 0.5 inches.

What is the surface area of the capsule? Round your answer to the nearest hundredth.

A. [tex]2.36 \, in^2[/tex]
B. [tex]3.93 \, in^2[/tex]
C. [tex]6.28 \, in^2[/tex]
D. [tex]3.14 \, in^2[/tex]



Answer :

To determine the surface area of the capsule, we need to break down the problem into the areas of its constituent parts: the cylinder and the two hemispherical ends.

1. Determine the radius of the hemispheres and the cylinder:
- Given the diameter is 0.5 inches, the radius (r) would be:
[tex]\[ r = \frac{0.5}{2} = 0.25 \text{ inches} \][/tex]

2. Calculate the surface area of the cylindrical part:
- We are given that the height (h) of the cylindrical part is 1 inch.
- The formula for the lateral surface area of a cylinder is:
[tex]\[ A_{\text{cylinder}} = 2 \pi r h \][/tex]
- Substituting the radius and the height into the formula gives:
[tex]\[ A_{\text{cylinder}} = 2 \pi (0.25)(1) = 0.5 \pi \approx 1.57 \text{ square inches} \][/tex]

3. Calculate the surface area of the hemispherical ends:
- The formula for the surface area of a sphere is:
[tex]\[ A_{\text{sphere}} = 4 \pi r^2 \][/tex]
- Since we have two hemispheres, together they form a complete sphere. For two hemispheres:
[tex]\[ A_{\text{hemispheres}} = \left(\frac{1}{2} \cdot 4 \pi r^2\right) \times 2 = 2 \pi r^2 \][/tex]
- Substituting the radius:
[tex]\[ A_{\text{hemispheres}} = 2 \pi (0.25)^2 = 2 \pi (0.0625) = 0.125 \pi \approx 0.79 \text{ square inches} \][/tex]

4. Calculate the total surface area of the capsule by adding the surface areas of the cylinder and the hemispheres:
[tex]\[ A_{\text{total}} = A_{\text{cylinder}} + A_{\text{hemispheres}} = 1.57 + 0.79 = 2.36 \text{ square inches} \][/tex]

Thus, rounding to the nearest hundredth, the total surface area of the capsule is:

Correct answer:

A. [tex]$2.36 \text{ in}^2$[/tex]