Forced vibration and resonance demonstrator This tabletop demonstrator makes it simple to observe forced vibration and resonance phenomena. The instrument consists of a bracket, five steel balls with different pendulum lengths, and a driven pendulum, all mounted on a plastic frame for stable classroom or laboratory use. Key benefits Clear visualization of forced vibration and resonance, helping students and instructors link theory to observable motion. Five pendulums with different lengths demonstrate how natural frequency varies with pendulum length, making comparisons immediate and intuitive. Compact, selfcontained setup is ready for demonstrations and easy to move between classroom and lab bench. Durable materials for repeated use in teaching environments, with steel balls for consistent mass and a plastic frame for stable mounting. Core features and specifications Components included: bracket, five steel balls on pendulums of different lengths, one driven pendulum. Materials: steel balls and plastic frame. Function: demonstrates vibration of an object under an external periodic force and resonance behavior of objects under selected conditions. Mounting: fixed on a plastic frame for stable display and use during experiments. How this product solves problems Makes abstract concepts visible by converting mathematical descriptions of resonance into a direct visual experiment. Reduces setup time compared with building a homemade apparatus, so instructors can spend more time on demonstration and discussion. Provides a consistent demonstration tool for repetitive teaching sessions and for comparative experiments that require the same starting configuration. Practical applications and use scenarios Physics lecture demonstrations: Show how different pendulum lengths respond to the same driving motion and identify which lengths reach maximum amplitude at resonance. Laboratory exercises: Use as a handson experiment to measure relative amplitudes and relate them to driving frequency and pendulum length. Science displays and teaching corners: Use as an attention drawing visual aid in a lab, science center, or classroom to illustrate fundamental oscillation concepts. Usage notes Place on a flat tabletop or lab bench for stable operation. Observe safety around moving parts and keep loose clothing and long hair clear of the pendulums during demonstration. Suitable for secondary and undergraduate physics education and general science outreach. This demonstrator provides a straightforward, reliable way to present forced vibration and resonance concepts using a set of steel pendulums mounted on a plastic frame.