A rigid body is made of three identical thin rods, each with length fastened together in the form. of letter H. The body is free to rotate about a horizontal axis that runs along the length of one of the arms of H. The body is allowed to fall from rest from a position in which the plane of the H is horizontal. What is the angular speed of the body when the plane of H is vertical?

A rigid body is made of three identical thin rods, each with length fa

1.	A rigid body is made of three identical thin rods, each with length fastened together in the form. of letter H. The body is free to rotate about a horizontal axis that runs along the length of one of the arms of H. The body is allowed to fall from rest from a position in which the plane of the H is horizontal. What is the angular speed of the body when the plane of H is vertical?
Answer» Solution :Using principle of conservation of mechanical enegy, we have `(mgl)/2+mgl=1/2Iomega^(2)` where `omega` is the angular speed of the rod when it becomes VERTICAL and `I=(ml^2/3)+ml^(2)`, assuming mass of EAC rod is `m`. SUBSTITUTING value of `I` in the above equation, we GET `omega=sqrt((9g)/(4l))`