Identical masses m are attached to identical springs of spring constant k suspended from the ceiling. With both masses hanging in their equilibrium positions, mass A is pulled down 10 cm and released while mass B is pushed up 10 cm and released. Which statement is correct?
A) Mass A will travel a smaller distance to its highest point than mass B will travel to its lowest point.
B) Mass A will travel a greater distance to its highest point than mass B will travel to its lowest point.
C) Masses A and B will travel equal distances between their highest and lowest points.
D) More work was done on mass A by the extending force than on mass B by the compressing force.
E) The total work done on mass A by the extending force was equal to the total work done on mass B by the compressing force.

Question

Quizplus · Accepted Answer

The springs and masses are symmetric, so the motion of mass A when pulled down and released is identical to the motion of mass B when pushed up and released. Therefore, both masses will travel the same distance between their highest and lowest points. Additionally, the work done on each mass is the same since they are subjected to forces that have equal magnitudes but opposite directions. Therefore, the answer is C.

Identical Masses M Are Attached to Identical Springs of Spring