Question

How do you do this question?

Answer 1

Explanation:

The moment of inertia of each disk is:

Idisk = 1/2 MR²

Using parallel axis theorem, the moment of inertia of each rod is:

Irod = 1/2 mr² + m (R − r)²

The total moment of inertia is:

I = 2Idisk + 5Irod

I = 2 (1/2 MR²) + 5 [1/2 mr² + m (R − r)²]

I = MR² + 5/2 mr² + 5m (R − r)²

Plugging in values:

I = (125 g) (5 cm)² + 5/2 (250 g) (1 cm)² + 5 (250 g) (5 cm − 1 cm)²

I = 23,750 g cm²