Answer to Question #246752 in Mechanics | Relativity for Malvus Nyamadzawo

Question

A uniform disc having a mass of 5kg and radius of gyration of 150mm is mounted on one end of a horizontal arm of length 200mm. the other end of the arm can rotate freely in a bearing. The disc is given a, clockwise spin of 250 rpm when seen from the end. Determine the motion of disc if the arm remains horizontal. [5] 

Answer 1

$m=5kg, l=200mm=0.2m, k=150mm=0.15m, N=250rpm$

$I=mk^2=5\times 0.15^2=0.1125kg.m^2$

$\omega=\frac{2\pi \times 250}{60}=26.18rad/s$

$C=I\omega \omega_p$

$mgl=I\omega \omega_p$

$5\times 9.18\times 0.2=0.1125\times 26.18\times \omega_p$

$\omega_p=3.33rad/s$