Three identical rods, each of length , are joined to form a rigid equilateral triangle. Its radius of gyration about an axis passing through a corner and perpendicular to the triangle is |
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a) |
b) |
c) |
d) |

Three identical rods, each of length , are joined to form a rigid equilateral triangle. Its radius of gyration about an axis passing through a corner and perpendicular to the triangle is |
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a) |
b) |
c) |
d) |

1 Answer

127 votes

**(a)**

The radius of gyration is the distance from the

axis of rotation at which if whole mass of the

body is supposed to be concentrated.

Here, the whole mass of the equilateral triangle

acts at point . So the distance is the radius of gyration of

this system. Now from triangle

or

or

or

Hence, the distance,

But, the distances are the same.

So,

Hence, the radius of gyration of this system is .

127 votes

127