Question

For a rigid body made of total N particles each of mass m, the radius of gyration about a given axis equals to –

• A. Root mean square values of the distance of the constituent particles from the given axis
• B. Distance of any of the constituent particles form the given axis
• C. mean of the distances of the constituent particles form the given axis
• D. Harmonic mean of the distance of consituent particles from the given axis.

Answer 1

Answer: (A)

Root mean square values of the distance of the constituent particles from the given axis

Answer 2

K = $\frac{I}{M}$ = $\sqrt{\frac{m_{1}r_{1}^{2} + m_{2}r_{2}^{2} + .... + m_{n}r_{n}^{2}}{m_{1} + m_{2} + .... + m_{n}}}$

if m₁ = m₂ = .... = m_n

k = $\sqrt{\frac{r_{1}^{2} + r_{2}^{2} + .... + r_{n}^{2}}{n}}$ = r_rms