Question

A 0.00600-kg bullet traveling horizontally with speed 1.00 103 m/s strikes a 19.3-kg door, embedding itself 10.4 cm from the side opposite the hinges as shown in the figure below. The 1.00-m wide door is free to swing on its frictionless hinges. (a) if so, evaluate this angular momentum. (if not, enter zero ) (------ kg.m^2/s ?). b) at what angular speed does the door swing open immediately after the collision? (----- rad/s ?). c) calculate the total energy of the bullet-door system and detemine whether it is less than or equal to the kinetic energy of the bullet before the collision. (KEf=-------- J?) (KEi= -------- J ?)

Answer 1

(a)
Any object which has a velocity vector which does not pass directly through the chosen axis has angular momentum about that axis.
The angular momentum of the bullet is transferred to the door:

L = mv