Pendeltests

Pendeltests, or pendulum tests, refer to a family of experiments in which a pendulum is used to study periodic motion and related physical properties. They are widely used in physics education to illustrate simple harmonic motion and in metrology and materials testing to measure gravitational acceleration, damping, stiffness, and impact energy.

Basic configurations include the simple pendulum, with a bob on a light string of length L, and more complex forms such as physical or compound pendulums where the moment of inertia about the pivot matters. For small amplitudes, the period T is approximately 2π√(L/g). For a rigid-body pendulum, T = 2π√(I/(m g d)), where d is the distance from the pivot to the center of mass. A torsion pendulum uses rotating stiffness and is sensitive to damping and elasticity. Advanced variants include Kater's pendulum for precise determination of g and the Foucault pendulum illustrating Earth's rotation.

Applications include measuring local gravitational acceleration, characterizing damping and resonance in mechanical systems, and, in materials testing, pendulum impact tests (such as the Charpy pendulum) to assess toughness. In education, pendulum experiments illustrate energy exchange and test the limits of the small-angle approximation. Modern setups often employ sensors, photogates, or video analysis to improve timing accuracy.

Limitations and sources of error include air resistance, pivot friction, string or rod elasticity, and amplitude effects. Accurate measurements require careful calibration, correction for systematic biases, and, for high-precision work, specialized pendulums like Kater-type configurations.

See also: Foucault pendulum; Kater's pendulum; Charpy pendulum test; simple pendulum.