Question

Find the moment of inertia of a sphere about a tangent to the sphere, while the mass of the sphere is M and the radius of the sphere is R.
A. `2/5 MR^(2)`
B. `6/5 MR^(2)`
C. `4/5 MR^(2)`
D. `7/5 MR^(2)`

Answer 1

Correct Answer - d
Moment of inertia of the solid sphere of mass M and radius R about any diameter is
`I_("diameter") = 2/5 MR^(2)`
According to theorem of parallel axes
`I_("tangent")=I_("diameter") + MR^(2)`
`=2/5MR^(2)+MR^(2)=7/5MR^(2)`