in the ideal apparatus shown in fig. 4.38, 2.0 kg. what is m2 if both masses are at rest? how about if both masses are moving at constant velocity? Exercise 72

i think its

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )

v=ir = 3x15 =45 v