Question

A thin rod of uniform cross-section is made up of two sections. The first part is wooden
having length of 50 cm and mass 0.6 kg. The second is of steel having length 30 cm
and mass 3 kg. Find moment of inertia of the rod, about transverse axis passing
through the junction of the two sections.

Answer 1

Answer:

The moment of inertia of the rod about the transverse axis is 0.42 kgm².

Explanation:

Step 1: Write down the formulas necessary.

The formula for getting inertia is given as :

Inertia = m1r1² + m2r2² +.....

M = mass of the object.

R = Radius from the axis in meters.

Step 2: Do the necessary conversions. In this case we convert cm to meters.

100 cm = 1 meter.

Wooden = 50/100 = 0.5 meters.

Steel = 30/100 = 0.3 meters.

Step 3 : Identify the given values.

M1 = 0.6 kg

R1 = 0.5 meters.

M2 = 3 kg

R2 = 0.3 meters.

Step 4 : Substitute the values in the formula in step 1.

0.6 × 0.5² + 3 × 0.3² = 0.42

The moment of inertia is therefore given by 0.42 Kgm²