# A uniform rod of mass 2 kg is hinged at one end .The rod is kept in the horizontal position by a massless string tied to point . Find the reaction of the hinge (in N) on end of the rod at the instant when string is cut  ## Question ID - 101435 :- A uniform rod of mass 2 kg is hinged at one end .The rod is kept in the horizontal position by a massless string tied to point . Find the reaction of the hinge (in N) on end of the rod at the instant when string is cut  3537

(5)

When the string is cut, the weight of the rod constitutes torque about the hinge, so (i)

According to Newton's second law, (ii)

Where is the angular acceleration of the rod about the end . From Eqs. (i) and (ii), we get Or Here , therefore Acceleration of the CM of the rod is Again by Newton’s second law, Or  Next Question :

A point mass is tied to one end of a cord whose other end passes through a vertical hollow tube, caught in one hand. The point mass is being rotated in a horizontal circle of radius 2 m with a speed of 4 m/s. The cord is then pulled down so that the radius of the circle reduces to 1 m. Complete the ratio of kinetic energies under the final and initial states  