Maria wants to find the surface area of a steel rod that is in the shape of a right circular cylinder. The diameter is 0.50 inches, and the length is 36 inches. What is the surface area? Use 3.14 for π .(1 point) Responses 56.52 inches2 56.52 inches squared 114.61 inches2 114.61 inches squared 0.39 inches2 0.39 inches squared 56.91 inches2

1 answer

To find the surface area of a right circular cylinder, we use the formula:

\[ SA = 2\pi r^2 + 2\pi rh \]

where:

  • \( r \) is the radius of the base,
  • \( h \) is the height (or length) of the cylinder,
  • \( \pi \) is approximately 3.14.

Given:

  • Diameter = 0.50 inches, so the radius \( r \) is half of that: \[ r = \frac{0.50}{2} = 0.25 \text{ inches} \]
  • Length \( h = 36 \) inches.

Now, we substitute these values into the formula:

  1. Calculate the area of the two circular bases: \[ 2\pi r^2 = 2 \times 3.14 \times (0.25)^2 = 2 \times 3.14 \times 0.0625 = 2 \times 3.14 \times 0.0625 = 0.3925 \text{ inches}^2 \]

  2. Calculate the lateral surface area: \[ 2\pi rh = 2 \times 3.14 \times 0.25 \times 36 = 2 \times 3.14 \times 9 = 56.52 \text{ inches}^2 \]

  3. Combine both areas to find the total surface area: \[ SA = 0.3925 + 56.52 = 56.9125 \text{ inches}^2 \]

Since we are looking for a rounded answer, we can round this value: \[ SA \approx 56.91 \text{ inches}^2 \]

Among the provided options, the closest one is:

56.91 inches².