NTA Abhyas JEE Main2020PhysicsRotational MotionPractice
A uniform rod of mass M 1 is hinged at its upper end as shown in the figure. A particle of mass M 2 which is moving horizontally, strikes the rod elastically at its midpoint. If the particle comes to rest after collision, then the value of M 1 M 2 is
Correct answer
0.75
Step-by-step solution
Conserving angular Momentum about the hinge, just before and after the collision L H = M 2 v L 2 = M 1 L 2 3 ω ω = 3 M 2 v 2 M 1 L e = 1 , v C M = v = ω L 2 ⇒ 2 v L = 3 M 2 v 2 M 1 L ⇒ M 1 M 2 = 3 4 = 0.75