Identical particles are placed at the 50-cm and 80-cm marks on a metre stick of negligible mass. This rigid body is then mounted so as to rotate freely about a pivot at the 0-cm mark on the metre stick. If this body is released from rest in a horizontal position, what is the angular speed of the metre stick as it swings through its lowest position?
A)4.2 rad/s
B)5.4 rad/s
C)4.6 rad/s
D)5.0 rad/s
E)1.7 rad/s

Question

Quizplus · Accepted Answer

The potential energy lost by the particles as they fall is converted into rotational kinetic energy. Using conservation of energy and the parallel axis theorem, the angular speed can be calculated to be approximately 5.4 rad/s.

Identical Particles Are Placed at the 50-Cm and 80-Cm Marks