Question

An object consists of a rod (of length 4.0 m and negligible moment of inertia) to which five small 1.0-kg massesare attached, one at each end and one at each point on the rod 1.0 m from each end. (The masses are one meterapart.) The moment of inertia of this object about an axis perpendicular to the rod and through one of the endmasses

Answer 1

I = 30 kg m²

Step-by-step explanation:

given,

length of rod = 4 m

mass of the 5 small masses = 1 kg

masses are kept at an interval of 1 m

Moment of inertia of the object = ? from the end mass

now distance of the masses from the end

r₁ = 1 m r₂ = 2 m r₃ = 3 m r₄ = 4 m

hence, the moment of inertia

I = I₁ + I₂ + I₃ + I₄ + I₅

I = mr₁²+ mr₂² + mr₃² + mr₄² + mr₅²

I = 1 x 0²+ 1 x 1² + 1 x 2²+ 1 x 3² + 1 x 4²

I = 1 + 4+ 9 + 16

I = 30 kg m²

hence, the moment of inertia of the object is I = 30 kg m²