Question

Calculate area moment of inertia for a circular cross-section with 3 mm diameter:

28 mm4


254 mm4


7 mm4


4 mm4


81 mm4

Answer 1

Option D: 4 mm⁴

Step-by-step explanation:

Formula for area moment of inertia for a circular cross-section is;

I = πd⁴/64

We are given diameter;

d = 3 mm

Thus;

I = π × 3⁴/64

I = 3.98 mm⁴

Approximating to a whole number gives;

I = 4 mm⁴