A complete cylindrical drill of radius 6 cm is
made in a solid cylinder with base radius 8 cm
and height 10 cm. Total surface area of this hol-
low cylinder will be
best answer will be marked as BRAINLIEST
Answers
Answer:
Total Surface area of hollow cylinder = 923.16 cm²
Step-by-step explanation:
Outer redius of Cylinder Ro = 8 cm
Inner redius of cylinder Ri = 6 cm (after drilling)
Height of the cylinder H = 10 cm
Find - Total serface area of the hollow cylinder.
There are total 4 serfaces in given cylinder.
1 - Area of inner cylindrical surface Ai = 2πRi × H
∴ Ai = 2×3.14 × 6 × 10
∴ Ai = 376.8 cm² ... (1)
2 - Area of outer cylindrical surface Ao = 2π Ro × H
∴ Ao = 2 × 3.14 × 8 × 10
∴ Ao = 502.4 cm² .....(2)
3 & 4 - Area of Top and bottom ring = At = Ab = (π/4) × (R0² - Ri²)
∴ At = Ab = (3.14/4) × (8² - 6²)
∴ At = Ab = 0.785 ×(64-36)
∴ At = Ab = 0.785 × 28
∴ At = Ab = 21.98 cm² .....(3)
Total Surface area of hollow cylinder
A = Ai + Ao + At + Ab
∴ A = 376.8 + 502.4 + 21.98 + 21.98
∴ A = 923.16 cm²
Total surface area of hollow cylinder = 923.16 cm²
Answer:
1056 cm²
Step-by-step explanation:
Outer radius of Cylinder = 8 cm
Inner radius of cylinder Ri = 6 cm (after drilling)
Height of the cylinder H = 10 cm
Find - Total surface area of the hollow cylinder.
There are total 4 surfaces in given cylinder.
Outer surface area = 2π * Outer radius * height
= 2π * 8 * 10 cm²
= 160π cm²
inner surface area = 2π * inner radius * height
= 2π * 6 * 10 cm²
= 120π cm²
Bottom surface + top surface = 2 * π (Outer radius² - Inner Radius²)
= 2π(8² - 6²)
= 56π cm²
Total surface Area = 160π + 120π + 56π cm²
= 336π cm²
π = 22/7
= 336 (22/7)
= 48 * 22
= 1056 cm²
Total surface area of this hollow cylinder will be 1056 cm²