Turning point

Definition

A turning point is a critical point in a potential energy diagram where the kinetic energy of a particle is zero, and it changes direction. These points occur when the total mechanical energy equals the potential energy.

5 Must Know Facts For Your Next Test

1. A turning point occurs where the kinetic energy $K = 0$, meaning all the mechanical energy is potential.
2. At a turning point, the velocity of the particle momentarily reaches zero before reversing direction.
3. In a potential energy diagram, turning points are found at intersections of the total mechanical energy line with the potential energy curve.
4. The stability of these points can be analyzed by examining second derivatives: minima are typically stable (stable equilibrium), while maxima are unstable (unstable equilibrium).
5. The concept of turning points is crucial in understanding oscillatory motion, as they define the limits of an object's displacement.

Review Questions

• What condition characterizes a turning point in terms of kinetic and potential energy?
• How does one identify turning points on a potential energy diagram?
• What does it mean for a turning point to be stable or unstable?

Related terms

Potential Energy: The stored energy in an object due to its position or configuration.

Total Mechanical Energy: The sum of kinetic and potential energies in a system, which remains constant if only conservative forces act.

Equilibrium: A state where net forces and net torque acting on an object are zero; can be stable, unstable, or neutral.