Question

Radius of gyration of a disc rotating about an Axis perpendicular to its plane and passing through its centre is
R/√2
R/√3
R/3
R/2

Answer 1

Answer:

option 1

$r \div \sqrt{2}$

Explanation:

I=mr^2/2

=mk^2

on solving K=R/root2

Answer 2

Radius of gyration of a disc rotating about an Axis perpendicular to its plane and passing through its centre is R/√2 .

R= radius of the disc

K= radius of gyration

M= moment of inertia

Here,

I = MR²/2

MR²/2= MK²

Therefore, M gets cancelled and R²/2=K²

Squarying both the sides we get ;

K = R/√2

Therefore, Radius of gyration of a disc rotating about an Axis perpendicular to its plane and passing through its centre is R/√2.

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