Question

Show that moment of inertia of a uniform circular lamina about a tangent in its plane is 5/4 mr^2 where m is mass ad r is radius

Answer 1

Answer:

moment of inertia of disc at tangent=5/4mr²=I +mr² (by parallel axis theorem)

I=5/4mr²-mr²=1/4mr²

by perpendicular axis theorem

I+I=I°(perpendicular to plane)

1/4mr²+1/4mr²=mr²/2

Answer 2

The previous answer was by theorem of perpendicular axis whereas my answer is by theorem of parallel axis