Steel Extension Spring, 56 x 19mm Subcategory_Rulers and Measuring sized to drop different loads

sized to drop different loads into a circuit without rewiring

Acrylic bell-in-vacuum jar with an internal 4-6V DC electric bell that fades and falls silent as the enclosed air is removed

Range 10Hz to 300Hz/sec

Nickel anode-and-cathode pair fitted in a rubber bung for the student electrolyzer

providing a high-density bob for pendulum and collision-momentum student investigations

Steel Extension Spring, 56 x 19mm Subcategory_Rulers and Measuring sized to drop different loads19mm diameter steel extension spring at 56mm rest length, stretching to approximately 290mm under load, sized for hands on Hooke's Law measurement with hanging weights.