Two unequal masses hang from either end of a massless cord that passes over a frictionless pulley. Which of the following is true about the change in gravitational potential energy U) and the change in kinetic energy of the system K) after the masses are released from rest? A) "$\Delta$U 0" B) "$\Delta$U = 0 and $\Delta$K 0" C) "$\Delta$U 0 and $\Delta$K

Question

Two unequal masses hang from either end of a massless cord that passes over a frictionless pulley. Which of the following is true about the change in gravitational potential energy U) and the change in kinetic energy of the system K) after the masses are released from rest? A) "$\Delta$U < 0 and $\Delta$K > 0" B) "$\Delta$U = 0 and $\Delta$K > 0" C) "$\Delta$U < 0 and $\Delta$K = 0" D) "$\Delta$U = 0 and $\Delta$K = 0" E) "$\Delta$U > 0 and $\Delta$K < 0"

Quizplus · Accepted Answer

The gravitational potential energy decreases ($\Delta$U < 0) as the heavier mass descends and the lighter mass ascends. The kinetic energy increases ($\Delta$K > 0) because the system starts moving from rest.

Two Unequal Masses Hang from Either End of a Massless Δ\DeltaΔ

Two Unequal Masses Hang from Either End of a Massless $\Delta$