At theta = -theta_max, which quantity is maximum?

At theta = -theta_max, which quantity is maximum?

• A. Kinetic energy
• B. Potential energy
• C. Restoring force
• D. Tangential acceleration

Answer: (B)

At the turning point where the angle is at its extreme, the object is momentarily at rest, so kinetic energy is zero. The height is the largest there, so gravitational potential energy is at its maximum. While the restoring force (and thus tangential acceleration) is nonzero and can be large, the definite standout at this instant is the energy stored as potential energy, which is greatest when the displacement is greatest.

At the turning point where the angle is at its extreme, the object is momentarily at rest, so kinetic energy is zero. The height is the largest there, so gravitational potential energy is at its maximum. While the restoring force (and thus tangential acceleration) is nonzero and can be large, the definite standout at this instant is the energy stored as potential energy, which is greatest when the displacement is greatest.