1. Four identical masses rotate about a common axis, 1.2 meters
from the center. Each mass
is 2.5 kg, and the system rotates at 2π rad/sec. The rods
connecting them are assumed to
be massless. Find the total angular momentum of this system.
A. 14.4 kg m2
/s
B. 90.5 kg m2
/s
C. 75.4 kg m2
/s
D. 18.8 kg m2
/s
E. 50.1 kg m2
/s
2. The four masses in question #1 are then pulled toward the
center until their radii are 0.5
meters. This is done in such a manner that no external torque acts
on the system. What
is the new angular speed of the system?
A. 36.2 rad/s B. 2.5 rad/s
C. 6.3 rad/s D. 4.7 rad/s E. 0.7 rad/s