# a rod of lenght L and mass M is hinged in vertical plane about its centre and is free to move.a insect falls on the rod with a velocity V at the distance L/4 from its centre and sticks to it. immediately after falling the insect starts moving so that rod rotates with constant angulat velocity. find its velicity at any time t.this question was asked by iit i dont understand if the insect is on the rod it applies normal force to the rod which will provide torque considering the rod only as the system there is a torque acting on it then how can it rotate with constant angular velocity.

Saurabh Kumar
askIITians Faculty 2400 Points
8 years ago
Initially, we need to assume the conditio of the rod in horizontal situation.
Initially tha insect has am angular momentum about the point O ans so when it comes in contact with the rod both will rotate about O.
If ‘w’ is the initial angular velocity, by conservation of angular momentum, i.e.
Mvr = Iw

Proceed in this way and apply the concept, you will get the solution.
Good Luck........................................................