Question

The moment of inertia of an uniform solid cylinder about it's geometrical axis is 8 units. The moment of inertia about the axis tangential to one of plane circular faces, i.e., about diameter of the circular base is (length of cylinder is 3 times it's radius)

• A. 52 units
• B. 26 units
• C. 104 units
• D. 49 units

Answer 1

The correct option is A 52 units

In this question we have to find $I$ above

$\begin{array}{c}I=\frac{m{R}^2}{4}+\frac{m{L}^2}{12}\\ =\frac{m{R}^2}{4}+\frac{9m{R}^2}{12}\\ =m{R}^2\\ ThisisIaboutmidpointoflength\\ \\ Now\\ I=I_c+m{d}^2\\ =m{R}^2+\frac{m{l}^2}{4}\\ =\frac{13m{R}^2}{4}\\ =\frac{13}{4}\times 16units\\ =52units\end{array}$