Question

The radius of gyration of a disc of mass 100 g and radius 5 cm about an axis passing through its centre of

gravity and perpendicular to plane is :

a) 6.54 cm b) 3.54 cm

c) 1.52 cm d) 2.57 cm

Answer 1

I= mr²/2 for the axis passing through the centre and perpendicular to the plane

I = mk²

hence K² = r²/2

k² = 25/2

k² = 12.5

k = 3.54 cm