Question

A uniform rod of mass m and length 'l' is attached to smooth hinge at end A and to a string at end B as shown in figure. It is at rest initially. The angular acceleration of the rod just after the string is cut is:

Answer 1

Answer:

torque =change in momentum

F△t=mv(linear momentum)………i

and (Fl2)△t=ml212ω (angular momentum)..ii

Dividing eqn i and ii we get

2=12vωl⇒ω=6vl

using S=ut

Displacement of CM is π2=ωt=(6vl)t

and =vt

Dividing we get

2xπ=l6⇒x=πl12

coordinates of A will be [πl12+l2,0