Question

Moment of intertia of a solid sphere about its diameter is 25 kg m². Calculate its moment of inertia about a tangent.

Answer 1

Moment of inertia of a solid sphere about its diameter,

I_d = `2/5 M R^2`

25 = `2/5 M R^2`

MR² = `(25 xx 5)/2`

MR² = `125/2`

∴ `I_"tangent"` = I_d + MR²

= `25 + 125/2`

= `175/2`

= 87.5 kg.m²