To find the surface area of the bundle of pencils, we need to calculate the lateral surface area of the cylinder and the surface area of the two circular ends.
The lateral surface area of a cylinder can be calculated using the formula:
Lateral surface area = 2πrh
where r is the radius of the cylinder and h is the height (or length in this case) of the cylinder.
Given that the diameter of the cylinder is 0.5 cm, the radius (r) is half of the diameter:
r = 0.5 cm / 2 = 0.25 cm
h = 19 cm
Lateral surface area = 2 * π * 0.25 cm * 19 cm
Lateral surface area = 2 * 3.14 * 0.25 cm * 19 cm
Lateral surface area = 2 * 3.14 * 4.75 cm
Lateral surface area = 29.8 cm²
The surface area of the two circular ends can be calculated using the formula for the area of a circle:
Surface area of two circles = 2 * π * r²
Surface area of two circles = 2 * 3.14 * (0.25 cm)²
Surface area of two circles = 2 * 3.14 * 0.0625 cm²
Surface area of two circles = 0.3925 cm²
Therefore, the total surface area of Ming's bundle of pencils is:
Total surface area = Lateral surface area + Surface area of two circles
Total surface area = 29.8 cm² + 0.3925 cm²
Total surface area = 30.1925 cm²
So, the surface area of Ming's bundle of pencils is 30.1925 cm².
Ming had 13 unsharpened pencils bundled in the shape of a cylinder. Of the diameter is 0.5 cm and the length is 19 cm, what is the surface area of Ming's bundle of pencils?
1 answer
1 answer