Question
2. (33 points) The figure below shows the overhead view of a uniform rod of length 0.450 m and mass 4.53 kg that can rotate in a horizontal plane about the vertical axis p, through its center. The rod is initially at rest when a bullet of mass 2.80 g traveling in the rotation plane is fired into one end of the rod. The angle between the rod and the path of the bullet is theta = 55.0 degree. The speed of the bullet before the impact is v = 2.1 km/s. What is the angular momentum of the bullet -rod system after the impact? Assume that the bullet becomes lodged in the rod.
Explanation / Answer
Note that angular momentum has to be conserved. Thus,
whether before or after the impact,
Ltot = m v (L/2) sin 55 = 1.084 kg m^2/s [ANSWER]