For a simple pendulum, a graph is plotted between its kinetic energy (KE) and potential energy (PE) against its displacement d. Which one of the following represents these correctly? (graphs are schematic and not drawn to scale)
Options

Question

For a simple pendulum, a graph is plotted between its kinetic energy (KE) and potential energy (PE) against its displacement d. Which one of the following represents these correctly? (graphs are schematic and not drawn to scale)

Options

G1 Physics · Accepted Answer

For a pendulum in SHM, potential energy U=(1/2)kx² is an upward-opening parabola with minimum at d=0. Total energy is constant, so K=E-U is a downward-opening parabola with maximum at d=0 and zero at the extremes. The graph with these two complementary parabolas is option 2.