Order early for pre-holiday delivery. Flinn will be closed December 24th, 2025,
through January 4th, 2026, reopening Monday, January 5th, 2026.
Orders received after 10:30 AM Central Time on Tuesday, December 23rd, 2025,
will ship after we return.
Price: $37.31
In Stock.
Dual-purpose, heavy-duty metal ball can double as a pendulum bob or as the key element in a dramatic inertia demonstration. Use one of the provided eyelets, attach a string, suspend the bob and you have a large demonstration pendulum.
Attach another string to the bottom eyebolt and let it hang down from the bob. Grasp the lower string and jerk it downward quickly. Which string breaks? Which string breaks if you pull on the lower string in a slow, even fashion? A very dramatic demonstration of the Law of Inertia. Your students will remember the concept for a long time.
The solid zinc ball weighs 454 grams. Fitted with 3 eye bolts. Eye bolts have 3/8" ID dia .