A rod AB of mass M and length L is lying on a horizontal frictionless surface. A particle of mass m travelling along the surface hits the end A of the rod with a velocity v0 in a direction perpendicular to AB. The collision in elastic. After the collision the particle comes to rest (a). Find the ratio m/M
I just want to know why the angular momentum is conserved about the center of mass. Why can't we take any other point on the rod to conserve angular momentum as no external torque is acting on the system.I am a a getting different value for angular velocity if i try to conserve angular momentum about any point except for center of mass.