A uniform rod lies in a horizontal plane and is attached to a frictionless hinge at…
PHYSICS · Single correct · AP · Physics 1: Algebra-based · Energy and Momentum of Rotating Systems · Energy and Momentum of Rotating Systems
Problem
A uniform rod lies in a horizontal plane and is attached to a frictionless hinge at one end. A small lump of clay moving in the plane strikes the rod and sticks, causing the rod–clay system to rotate about the hinge. Which statement best explains why angular momentum about the hinge can be used to analyze the collision?
(a) The hinge exerts no force on the rod during the collision
(b) The linear momentum of the clay–rod system is conserved during the impact
(c) The net external torque about the hinge during the brief impact interval is negligibly small
(d) The moment of inertia of the rod remains essentially constant during the collision