Ming has 12 unsharpened pencils bundled in the shape of a cylinder. If the diameter is 0.5 cm and the length is 19 cm, what is the surface area of Ming’s bundle of pencils? Use 3.14
To find the surface area of the cylinder of pencils, we need to find the area of the two circular ends and the lateral surface area.
1. Area of one circular end:
The radius of the circular end is half of the diameter, so it is 0.25 cm.
Area = πr^2 = 3.14 * (0.25)^2 = 0.19625 cm^2
Since there are 2 circular ends, the total area of the two circular ends is: 2 * 0.19625 = 0.3925 cm^2
2. Lateral surface area:
The lateral surface area of a cylinder is given by the formula: 2πrh, where r is the radius and h is the height (length of the cylinder).
Lateral surface area = 2 * 3.14 * 0.25 * 19 = 28.66 cm^2
3. Total surface area:
Total surface area = 2 * circular end area + lateral surface area
Total surface area = 0.3925 + 28.66 = 29.0525 cm^2
Therefore, the surface area of Ming's bundle of pencils is 29.0525 cm^2.