Question

Three identical rods, each of length L, are joined to form a rigid equilateral triangle. Its radius of gyration about an axis passing through a corner and perpendicular to the plane of triangle is ?​

Answer 1

Secondary School Physics 8+4 pts

21. three identical uniform rods each of length l are joined to form a rigid equilateral triangle .its radius of gyration about an axis passing through a corner and perpendicular to the plane of the triangle is

Report by Pr5i0yajyotimaiya 18.11.2016

Answers

SharinkhanExpert

Mol of rod passing through the center= 1/12 ML²

Mol of rod passing through one side= 1/3 ML²

AP= √3/2 L

Mol of BC through the prependicular A

= 1/12 ML² + M(√3/2 L)²

= 1/12 ML² + √3/4 ML²

= 5/6 ML²

By the principle of superposition

= 1/3 ML² + 1/3 ML² + 5/6 ML²

= 9/6ML²

= 3/2 ML²

radius of gyration

k = √3/2 ML²/ 3M

= L/√2